DeltaOHM HD2010UC/A Operating Manual

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Operating manual

Integrating Sound Level Meter Spectrum Analyzer

HD2010UC/A

www.deltaohm.com

English

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1. Microphone.

2. Preamplifier.

3. Preamplifier or extension cable connector.

4. Symbol showing measurement status: RUN, STOP, PAUSE, RECORDING or HOLD.

5. Keypad LEFT key: in graphic mode, it moves the selected cursor towards lower values.

6. Keypad CURSOR key: in graphic mode, it allows to select one or both of the two cursors.

7. HOLD key: it temporarily stops display updating.

8. MENU key: it activates the different configuration menus of the instrument.

9. REC key (recording): combined with START/STOP/RESET, it activates data recording on

memory. When pressed for at least 2 seconds, the displayed data can be stored in memory as a single record; alternatively, the Auto-Store mode can be activated.

10. PAUSE/CONTINUE key: pauses integrated measurements. From PAUSE mode, integrated

measurements can be resumed by pressing the same key. In PAUSE mode, press START/STOP/RESET to reset measurements.

11. SELECT key: enables modification mode of displayed parameters by selecting them in se-

quence.

12. ENTER key. It confirms entered data or edited parameters.

13. LEFT key: in the menu, it is used when editing parameters with attribute. In graphic mode, it

reduces the vertical scale.

14. M12 connector for RS232C multi-standard serial port and USB.

15. Auxiliary power supply connector.

16. DC output connector (∅ 2.5mm jack).

17. DOWN key: in the menu, it selects the next line or decreases the selected parameter. In graphic

mode, it increases the vertical scale levels; the graph is shifted downwards.

18. RIGHT key: in the menu, it is used when editing parameters with attribute. In graphic mode it

extends the vertical scale.

19. MODE key: selects in circular order the instrument’s different view modes, from the display of

5 channels in numeric format, to the profile, to the octave and third octave spectrum (“Third Octave” option) and to the statistics analysis screens.

20. UP key: in the menu, it selects the previous line or increases the selected parameter. In graphic

mode, it decreases the vertical scale levels; the graph is shifted upwards.

21. START/STOP/RESET key: when pressed in STOP mode, it starts the measurements (RUN

mode). In RUN mode, it stops the measurements. When pressed in PAUSE mode, it resets the integrated measurements, such as Leq, SEL, MAX/MIN levels, etc.

22. PROG key: activates the program selection mode.

23. PRINT key: transfers the displayed data to the serial port. When pressed for more than 3 sec-

onds, it enables the continuous printing (Monitor). Monitoring will be stopped by pressing the key once more.

24. ON/OFF key: turns the instrument on and off.

25. Keypad RIGHT key: in graphic mode, it moves the selected cursor towards higher values.

26. Battery symbol: indicates the battery level. The more the symbol is empty, the more the battery

has run down.

27. LINE: un-weighted output connector (∅ 3.5mm jack).

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CONNECTOR FUNCTION

The instrument is equipped with five connectors: one in front, one to the side and three at the bottom. The figure on page.2 shows: n. 3 - 8-pole DIN connector for preamplifier or extension cable. The connector, located on the

instrument front face, has a positioning notch and a screw ring nut to ensure proper locking.

n.14 - M12 connector for RS232C multi-standard serial port and USB. For the connection to a

COM port (RS232), you have to use the dedicated serial null-modem cable (code HD2110RS), fitted with a 9-pole female connector conforms to class 1 specifications according. As alternative the sound level meter can be connected to a PC USB port by using the dedicated cable (HD2110USB), fitted with type A USB connector.

n.15 - Male connector for external power supply (∅ 5.5mm-2.1mm socket). It requires a

9…12Vdc/300mA power supply. The positive (pole) power supply must be connected to the central pin.

n.16 - Jack (∅ 2.5mm) or the analogue (DC) A weighted output with FAST constant time up-

dated 8 times/s.

n.27 - Jack (∅ 3.5 mm) for the analogue (LINE) un-weighted output placed on the right side of

the conical part/detail.

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INTRODUCTION

HD2010UC/A is an integrating portable sound level meter performing either spectral or statistical analysis. The instrument has been designed combining maximum usage flexibility, cheapness, and simplicity of use. Attention has been paid to the possibility of adjusting the instrument to regulatory modifications, and to the necessity of meeting its users’ needs of today and tomorrow. The HD2010UC/A can be integrated with other options to extend its application scope at any time; the firmware can be updated directly by the user by means of the supplied Noise Studio program. The HD2010UC/A conforms to IEC 61672-1 of 2002, IEC 60651 and IEC 60804 specifications with class 2 or class 1 tolerances. The constant percentage bandwidth (CPB) filters meet IEC 61620 class 1 specifications. The HD2010UC/A is an integrating sound level meter and analyzer suitable for the following applications:

• Assessment and monitoring of the environmental noise level,

• Spectral analysis by octave bands from 31.5Hz to 8kHz,

• Optional (HD2010.O1) spectral analysis by third octave bands from 25Hz to 12.5kHz,

• Statistical analysis with percentile levels calculation from L

to L99

• Capture and analysis of sound events,

• Measurement at the workplace,

• Selection of personal protective equipment (SNR, HML and OBM methods),

• Soundproofing and acoustic treatment,

• Production quality control,

• Measurement of machine noise,

• Optional architectural and building acoustics measurements.

Using the HD2010UC/A sound level meter it’s possible to log the noise time profile with parallel frequency weightings and time constants acquisition. The sound level meter , automatically stores noise analysis of multiple acoustic descriptors as a data recorder, with a storing capacity of more than 23 hours at the maximum temporal resolution. For long ter m noise monitoring, it’s possible to record together, with a time period from 1 s to 1h, 5 programmable parameters, the average spectrum and complete statistical analysis: with the “Memory module” option HD2010.O0 (it doubles the standard memory capacity), the HD2020UC/A can store, with a time interval of 1min, the noise multi-parameter and statistical analysis for more than 10 days. For particular needs it’s possible to increase even further the memory capacity using the HD2010MC module. This device is supplied with a 2GB SD memory card.

The HD2010UC/A has a versatile trigger function for the noise event capture, with the additional possibility to filter false events; this is made verifying that the noise event level variation has a certain duration. For each identified event, it’s possible to record 5 integrated parameters (user defined), average spectra in octave and third octave bands and the noise levels probability distribution sampled during the specific event. The event parameters recording doesn’t exclude the normal and interval standard storing. The event trigger function can be started also manually pressing a key on the keyboard.

The advanced functions of HD2010UC/A analyser, allow multi-parameters profile acquisition in parallel with reports sequences with dedicated parameters, average spectra and complete statistical analysis. Moreover, during recording, trigger function allows to identify noise events and to record 5 user defined parameters, average spectrum and statistical analysis, all integrated during the event duration.

During data-logging are available up to 9 different markers to highlight the occurrence of specific situations to be considered in the time history post processing phase.

A timer allows to schedule a delayed acquisition start.

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Different recordings can be later recalled from internal memory and displayed on the graphical screen using the “Replay” function that shows the time history of recorded noise levels. The USB interface high transfer speed, combined with RS232 flexibility, allow fast data transfer from sound level meter internal memory to PC memory but also to control a modem or a printer. For example, in case the internal memory is not sufficient, that’s the case of long term monitoring, it’s possible to activate the “Monitor” function. Such function allows to transmit displayed data through the serial interface, recording them directly on PC memory.

The HD2010UC/A can be fully controlled via a PC using the multi-standard serial interface (RS232 and USB), using a dedicated communication protocol. Through RS232 serial interface it’s possible to connect the HD2010UC/A to a PC also by means of a modem.

Together with the logging of the overall noise level profiles, the spectral analysis is carried out in real time for octave bands and for third octave bands, as an option. The sound level meter calculates the spectrum of the sound signal twice a second and integrates it linearly for up to 99 hours. The average spectrum or the multi-spectrum profile starting from 1s, are displayed together with an A, C or Z wideband overall level; this allows a fast comparison between spectrum and overall level. Moreover the spectrum can be shown both as linear and as A or C frequency weighted, for a fast evaluation of the different spectral components audibility.

As a statistical analyser, the HD2010UC/A samples the sound signal 8 times per second with A-frequency weighting and FAST time constant, and analyses it statistically according to 0.5 dB classes. Statistical analysis is shown in a graphic form as probability distribution and cumulative distribut ion with percentile levels from L1 to L99.

For further analysis, the LINE un-weighted output allows to record the noise either on tape or directly on a PC equipped with a data acquisition card.

The calibration can be made either using an acoustic calibrator (type 1 or 2 according to IEC

60942) or the built-in reference generator. The electric calibration employs a special preamplifier and checks the sensitivity of the measuring channel, microphone included. A protected area in the non-volatile memory, reserved to factory calibration, is used as a reference in the user’s calibrations, allowing to keep instrument drifts under control and preventing the instrument from wrong calibrations. The user can check on site the complete sound level meter’s functionality thanks to a diagnostic program.

The HD2010UC/A sound level meter can perform the measurements required to evaluate workers’ noise exposure (D.L. N.81/2008, UNI 9432/2011 and ISO 9612/ 2011 standards). According to UNI EN 458, the personal protective equipment can be selected through octave band spectrum analysis (OBM method) and a comparison of the A and C-weighted equivalent levels that can be measured simultaneously (SNR method). If an undesired sound event produces an over-load indication, or simply alters the result of an integration, its contribution can be excluded using the versatile Back-Erase function. The impulsivity of a noise source is easily evaluated (according to criteria defined in UNI 9432 standard) measuring the A weighted equivalent sound pressure level with Impulse time constant (LAeqI). The cyclic, fluctuating and impulsive noise sources identification is simple thanks to the powerful recording functions of HD2010UC/A analyser which allows, using a single measurement setup, to solve the most of situations encountered in working environments. The combination of powerful measurement and recording functions of HD2010UC/A with the analysis functions of the post processing Noise Studio (supplied with all sound level meters) software module “Worker’s protection”, allows a fast and efficient management of noise measurements for health and safety evaluations in workplaces.

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The HD2010UC/A sound level meter is suitable for sound level monitoring, acoustic mapping, and the assessment of the acoustic climate with capture and analysis of sound events. When measuring traffic noise near airports, railways and roads, the sound level meter can be used as a multiparameter sound recorder, combining spectrum (option “Third octave” from 25Hz to 12.5KHz) and statistical analyser features. Remote electrical calibrations and diagnostic tests can be executed using its remote control functions.

The HD2010UC/A, sound level meter, with the “Third Octave” and “Reverberation Time” options, can perform all measurements prescribed by the regulations on building acoustics evaluation (ISO

140). The sound level meter powerful DSP calculates 32 spectra/second, and it can measure reverberation times both using the sound source interruption and the impulsive source integration technique according to UNI EN ISO 3382. The HD2010UC/A sound level meter analyses the noise level decays with the Ordinary Least Squares method, simultaneously both by octave from 125Hz to 4KHz and, if option HD2010.O1 is installed, by third octave bands from 100Hz to 12.5KHz according to survey, engineering and precision methods defined in UNI EN ISO 3382-1/2009 and 3382/2008.

The HD2010UC/A can be configured in accordance with different customers’ needs: the available options can be activated on the new instrument, as well as, later on, when requested by the user. The provided options are:

 “Third Octave” option

It adds a parallel bank of third octave filters from 25Hz to 12.5 kHz in class 1, according to IEC

61260. The filter bank works in parallel to all other measurements. The audibility of the different spectrum components can be evaluated applying A or C frequency weightings or thanks to the isophone (equal loudness level) curve calculation function of Noise Studio, a program supplied with the instrument.

 “Reverberation Time” option

Through this option the HD2010UC/A can carry out reverberation time measurements according to the techniques of the interruption of the sound source and of the impulsive source according to EN ISO 3382-2/2008 requirements. This measurement is made simultaneously for octave band from 125 Hz to 8 kHz and optionally for third octave band from 100 Hz to 10 kHz. The sampling interval equals 1/32s and the calculation of EDT, T10, T20 and T30 reverberation times is made automatically for all bands.

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HD2010UC/A BLOCK DIAGRAM

The block diagram shows the main elements of the HD2010UC/A sound level meter.

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THE MICROPHONE

The UC52 condenser microphone is pre-polarized (electret) and has a ½” standard diameter. The frequency response in free field is flat from 20Hz to 16kHz in type 1 HD2010UC/A version (UC52/1). Microphones used for type 2 precision sound level meter versions have a flat frequency response from 25Hz to 10KHz.

THE OUTDOOR MICROPHONE UNIT HD WME

The microphone unit HD WME is suitable for long term outdoor noise measurements, including from fixed unattended station. The unit is adequately protected from rain and wind; the heated preamplifier allows performing measurements within a wide weather condition range. The special preamplifier is fitted with a calibration circuit that uses a charge partition technique in order to calibrate the unit, inclusive of the microphone capsule. The output driver allows guiding cables up to 10m in length, without important losses.

HD WME unit must be positioned in vertical position to fulfil correctly its function as weather protection. Used in this way it can measure both community and aircraft noise (90° and 0°). Delta Ohm sound level meters apply spectral corrections to measurements in order to comply with

IEC61672 type 1 and type 2 tolerances.

Installation and uninstallation procedure is very easy; in this way periodical acoustic verification (using a standard ½ calibrator) of the microphone is as simple as for a standard measurement microphone.

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The unit is composed of a central body plus the following components:

• HD SAV3: wind-screen (3)

• HD WME1: ant-bird spike (4)

• HD WME2: rain shield (2)

• HD WME3: stainless steel support (1)

• Microphonic capsule with optimized free field correction

• Microphone preamplifier: HD2010PNE2W: heated preamplifier for UC52 microphone in-

cluding CTC calibrator and driver for up to 10m extension cable.

• Extension cable standard 5m length (10m on request).

For detailed information on the use of HD WME unit, please refer to the specific part of this manual on page 49; for information on assembling and disassembling the unit please refer to appendix on page 144.

THE PREAMPLIFIER

The preamplifier amplifies the weak signal provided by the microphone. It has a gain selectable between 0 and 20 dB and is supplied with a charge partition calibration device which allows to measure the frequency response of the whole amplification chain, microphone included as described on page 49). The output driver allows transmitting the microphone signal via a cable to a distance up to 10m. The preamplifier of HD2010UC/A together with UC52 microphone can measure signals up to 140 dB with a frequency response (excluding microphone) up to 40kHz The following models are available:

• HD2010PNE2: connector for ½” UC52 microphone and driver for up to 10m extension cables.

This preamplifier, supplied with CTC electric calibration device, can be directly plugged into the HD2010UC/A sound level meter or connected via extension cable (up to 10mt).

• HD2010PNE2W: heated preamplifier with connector for ½” UC52 microphone and driver for

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extension cables. This preamplifier, supplied with CTC calibration device, can be connected to sound level meters using the 5mt supplied extension cable (10m as option).

• HD2010PNE4: preamplifier for MC24E ¼” microphone. Equipped with CTC calibration device

for electric calibration and driver for cable up to 100m. Requires the HDP079A02 microphone adapter.

• HD2010PNE4H: preamplifier for MC24EH ¼” microphone. Equipped with CTC calibration

device for electric calibration and driver for cable up to 100m. Requires the HDP079A02 microphone adapter.

THE INSTRUMENT

The preamplifier signal comes to the instrument receiver and its output is sent to the LINE connector and to the A/D converter input. The A/D converts the analogue signal into the numeric format at 20 bits. The measurement dynamics, exceeding 140 dB, is divided into 5 ranges using a variable gain amplifier with steps of 10 dB, between 0 dB and 20 dB, positioned at the input.

Then the digitalized signal reaches the DSP for processing. The levels either wideband (A, C and Z) or with constant percentage bandwidth (both octave and third octave) are calculated in parallel in the DSP. Peak (C and Z) levels are also calculated. The levels calculated by the DSP are transmitted to the microprocessor for further processing, ready to be displayed, stored and printed.

The microprocessor controls all the instrument processes: management of the electrical calibrator, Flash memory, display, keyboard and multi-standard serial interface (RS232 and USB). The microprocessor also supplies the electrical signal corresponding to the A weighted instant level with FAST time constant, sent to DC output.

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DESCRIPTION OF DISPLAY MODES

The HD2010UC/A measures simultaneously 3 selectable parameters (statistic ones too) and displays them at a fixed frequency corresponding to 2 measurements/s; simultaneously measures the A weighted sound pressure level with FAST time constant and displays it at 8 samples/s. It calculates also the spectra by octave bands and by third octave bands (when the “Third Octave” option is active), with a maximum frequency of 2 spectra/s. As a statistical analyser, it calculates the probability and the cumulative distribution. To be able to display all these data, the HD2010UC/A, provides 6 different display modes as shown in the figures below.

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01:08:25

Tint= s

LFp

Leq

Lpk

dBA

dBC

Fig. 1 - SLM

Fig. 2 - Time Profile

Fig. 3 - Octave

Fig. 4 - Third Octave

Fig. 5 – Probability distribution

Fig. 6 – Percentiles levels

Press MODE at any time to jump from a screen page to the next one. The display will show: first the SLM screen with 3 measuring parameters in numeric format, the Profile screen of the A weighted sound pressure level with FAST time constant (L

AFp

), then the Octave screen with the octave spectra from 31.5 Hz to 8 kHz and, (if the “Third Octave” option is active) the third octave spectra from 25Hz to 12.5 kHz, the probability distribution and the percentile levels screens. . Upon power on, the sound level meter displays the SLM screen. Display of Octave and Third Octave display can be disabled using the specific parameters in the menu (Menu >> Statistic Analyser >> Display…). Also the Probability and Percentiles screens can be disabled, using parameter Menu >> Statistic Analyser >> Statistics Display (please see paragraph “DESCRIPTION OF MENU FUNCTIONS” on page 39)

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Some display indications are common to all display modes; they are (see picture):

• Measurement status indicator

• Overload/Under-range indicator

• Battery level indicator

The first symbol in the left corner at the top shows the measurement status of the sound level meter.

• RUN: the instrument is measuring.

• PAUSE: the calculation of integrated measure-

ments and the recording of measurement have been suspended. Instantaneous parameters are still being measured and displayed.

• REC: the instrument is measuring and re-

cording.

• STOP: the instrument is not making any meas-

urement.

• HOLD: the calculation of integrated measurements has come to the end of the set integration

interval, or HOLD was pressed.

• P (Print): indicates that printing is in progress.

• M (Monitor): indicates (flashing) that continuous data printing has been started.

• R (Replay): appears (flashing) when the “Memory Navigator” program is in use, to view a file

saved in the instrument memory (see page 46).

Just on the right of the symbol indicating the logging mode, there is the symbol showing a possible overload or under-range. An arrow directed upwards indicates that the input level has exceeded the maximum measurable level, while an arrow directed downwards indicates that the input level is lower than the minimum measurable level.

The maximum measurable level corresponding to the selected measurement range is given in the technical specifications (see page.94). The minimum measurable level is 80 dB lower than the maximum one. The noise levels for each frequency weighting are listed in the technical specifications. Using an appropriate parameter (MENU >> Instrument >> Measurement >> Overload Level) you can program the maximum measurable limit at lower levels (see page 94).

An empty arrow indicates that the limit has been exceeded, while a full arrow indicates that the overload is in progress.

The integration time Tint, programmable between 1s and 99h, is displayed to the right of the overload indicator. When the integration mode is set on MULT, the “Tint” symbol on the SLM will flash (see the “DESCRIPTION OF THE DIFFERENT INTEGRATION MODES” on page 29).

In the right corner at the top, there is the battery symbol. The more the symbol is empty, the more the battery has run down. When the instrument autonomy reaches 10%, corresponding to about 30 minutes, the battery symbol will start flashing. A protection device prevents the instrument from making measurements with insufficient battery levels and automatically switches off the instrument when the battery level is at the minimum.

The battery level, expressed in percentage, is visible in the menu main screen page and in the program page; press MENU and PROG to access them. To jump back to the measurement screen, press MENU and PROG again.

Pressing SELECT, you will select in sequence the parameters relevant to the displayed page. While the selected parameter flashes, use UP and DOWN to change it. Press ENTER to quit the selection mode (automatic exit after 10s).

In graphic display mode, use the UP, DOWN, LEFT and RIGHT keys to change the vertical scale parameters. The LEFT and RIGHT keys reduce and expand the vertical scale, while the UP

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and DOWN keys decrease and increase the levels of the vertical scale; the graph is so shifted upwards or downwards, respectively.

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SLM (SOUND LEVEL METER MODE)

This is the display mode upon power on. Three parameters (selectable among the following ones) can be displayed simultaneously:

• Instantaneous acoustic descriptors such as Lp, Leq(Short) and Lpk. The instantaneous pres-

sure level is displayed as the maximum level reached every 0.5s.

• Integrated acoustic parameters with wideband frequency weightings, such as L

pmax

, L

eq,

Ieq

and L

pkmax

, updated every 0.5s.

• Percentile levels selectable between L1 ad L99.

• Sound exposure level.

• Daily personal exposure level.

• Dose and daily Dose with programmable Exchange Rate, Criterion and Threshold Levels.

• Overload Time (in %).

The display is updated every 0.5 seconds.

The data recording depends on the integration mode selected (single or multi) and on the activation or not of the Auto-Store function change the recording functioning as described in the table below (see the chapter “DESCRIPTION OF THE DIFFERENT INTEGRATION MODES” on page 29).

Auto-Store: OFF Auto-Store: ON

Integration

SINGLE

Recording twice a second of the 3 parameters and 8 times a second of LAF. Automatic Stop at the end of the set integration interval.

Automatic recording of SLM page, together with OCTAVE and (as an option) THIRD OCTAVE, at the end of the set integration interval.

MULTIPLE

Recording twice a second of the 3 parameters and 8 times a second of LAF. Automatic reset of integrated levels at every integration interval.

Automatic recording of SLM page, together with OCTAVE and (as an option) THIRD OCTAVE, at intervals equal to the set integration time. At the beginning of each period, integrated levels and spectra are set to zero.

DISPLAY DESCRIPTION

Left at the top of the display there are the recording status symbol and the overload or underrange indicator (described at the beginning of this chapter). In the midst there is the integration interval and on the right the acquisition time (hours:minutes:seconds). When the integration mode is set on MULT (Menu >> Instrument >> Measurements >> Integr.: MULT), the “Tint” symbol flashes. The battery symbol is in the right corner, indicating battery level.

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LFp

Leq

Lpk

dBA

dBC

Integration interval

cquisition time

Maximum level

Minimum level

Displayed parameters

Bar showing istantaneous level

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The “analogue bar” shows the unweighted sound pressure instantaneous level in an 80 dB in- terval. Three measuring parameters are displayed under the analogue bar. All displayed parameters can be freely selectable among the available ones. There are no restrictions in the selection of frequency weightings. Measuring parameters are displayed with a shortened label, followed by the numerical value, by the unit of measurement, and, when necessary, by the frequency weighting. The correspondence between the label and the effective parameter is to be found on page 121. Integrated parameters like Leq (and Lmax or Lmin), which imply the accumulation of the sampled sound levels, are displayed with a series of dashes (- - - -) until the level remains lower than the minimum measurable level.

Before starting a new logging, the sound level meter automatically resets all measurements. If the mult iple integration mode is enabled (MENU >> Instrument >> Measurements >> Integration Mode: MULT), integrated levels will be automatically set to zero at regular intervals equal to the set integration time Tint.

With the Continuous Recording function, a series of values is stored every 0.5s together with the parameter displayed in the PROFILE screen, which corresponds to the A weighted sound pressure level with FAST time constant, computed 8 times a second. Each sample corresponds to the highest sound level (L

AFmx

) calculated every 0.125s on the level measured every 7.8ms.

SELECTING PARAMETERS

Some measuring parameters (integration interval, measuring range and the 3 parameters) can be changed directly via the SLM screen. Pressing SELECT you choose the different parameters in sequence. While the selected parameter flashes, you can change it with the UP and DOWN keys.

If a parameter with attribute is selected, like, for example, LFp (FAST weighted pressure level), the relative frequency weighting will also flash (A in the example in the figure). In this case, pressing UP and DOWN, you can modify the selected parameter without changing the attribute; for example, if you press DOWN, you can go from LFp A weighted to LSp A weighted. Pressing RIGHT you’ll jump to the attribute selection, which will be the only one to flash. Use then the UP and DOWN keys to change the attribute. For example, if you press UP, you can go from A weighted LSp to Z weighted LSp.

Pressing SELECT let you choose the next parameter; pressing ENTER, or automatically after approximately 10s, will let you exit the selection mode.

Also the integration mode (see page 29) can be set using the LEFT and RIGHT keys: press SELECT to choose the integration interval. When the numeric value of the integration interval flashes, press RIGHT to set the multiple integration mode or LEFT to set the single integration mode. When the integration mode is set on MULT, the “Tint” symbol flashes.

Parameters can be modified only when the instrument is in STOP mode: if you try to make changes to any of the parameters while the instrument is in a status other than STOP, you will be asked to stop the measurement in progress: pressing YES will stop recording and will allow you to go on modifying parameters; pressing NO recording will continue without interruption. The above settings can be made through the instrument configuration menus. See a detailed description on page 36.

BACK-ERASE FUNCTION (DATA EXCLUSION)

To stop a measurement in progress when recording, press the PAUSE/CONTINUE key. All data logged until the moment key was pressed are used for calculation of integrated parameters. However, there are some cases when it is useful to clear the measurements recorded just before

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pressing PAUSE, for example, because they were caused by unexpected events and not characterizing the sound being examined.

During measurement, press PAUSE/CONTINUE: integrated measurements update will be interrupted. At this point, press the LEFT arrow to delete the last recorded data.

The integration time value will be temporarily replaced by the word ERASE followed by the time interval (in seconds) to be deleted. Use the LEFT and RIGHT keys to increase or decrease the erase interval. Displayed integrated parameters change accordingly, allowing to choose the erase time depending on the effective need. When pressing PAUSE/CONTINUE again, measurement will start again and the integrated parameters will have been removed from the selected interval.

The erase maximum time, divided into 5 steps, is set from menu: MENU >> Instrument >> Measurement >> Max Back-Erase. Settable values are: 5, 10, 30 or 60 seconds, with 1s, 2s, 6s or 12s steps, respectively.

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TIME PROFILE MODE

This display mode presents the time profile of the A weighted sound pressure level with FAST time constant (L

AFp

). The integration time is equal to 1/8s and the last 100 measured samples are displayed. The HD2010UC/A sound level meter calculates the sound level 128 times per second (with a time period of 7.8ms) and displays the maximum level at intervals equal to 125ms.

Pressing HOLD, the display update will be stopped; however, the instrument continues meas-

uring and pressing HOLD again will restart display updating.

The HOLD status does not affect either Monitor (continuous printing) or recording operations. When the continuous recording is activated with the single integration mode, the integration time acts like a timer for data acquisition, stopping automatically the measurement when the time is elapsed.

This screen-page is not recorded in the Auto-Store mode.

DISPLAY DESCRIPTION

Fig. 7 - Description of the Profile mode display

The Fig. 7 presents the time profile of the A weighted sound pressure level with FAST time constant. The integration interval is shown in the left corner at the bottom of the display. Always at the bottom, in the centre, the display shows the measurement unit and the frequency weighting of the measuring parameter The amplitude of the vertical scale of the displayed graph corresponds to 5 divisions. The amplitude of each division is called “scale factor” of the graph and appears in the middle of the vertical axis.

Using the RIGHT (zoom +) and LEFT (zoom -) keys, this parameter is selectable in real time among 20dB, 10dB or 5dB by division.

Use the UP and DOWN arrows to set the graph full scale with steps equal to the selected scale factor, starting from the instrument full scale1. In this way, the graph can be shifted UP or DOWN, depending on the key you have pressed.

An “analogue” bar indicator on the display right side provides the unweighted instantaneous level of the input sound pressure level, as for the SLM mode bar.

During Recording mode, 4 values of the L

AFp

level are stored every 0.5s together with the SLM screen sound levels. Likewise, when the Monitor function is enabled, 4 values are sent to the interface every 0.5s.

The instrument full scale is determined by the selection of the input gain by choosing from the menu: MENU >> In-

strument >> Measurements>> Input gain.

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The integration mode do not influence this screen recording functioning. The sound level displayed on this screen can be used as source for the event trigger (see para-

graph “EVENT TRIGGER FUNCTION” on pag. 27).

USING THE CURSORS

To activate cursors on the graph, press CURSOR on the keypad. If you press CURSOR re-

peatedly, either L1 or L2 cursor, or both ΔL cursors in “tracking” will be activated in succession: the selected cursor will flash. Use the LEFT and RIGHT arrows on the keypad to move the selected cursor on the graph.

The second line at the top of the display shows the level of the measuring parameter and the time indicated by the active cursor or the time interval and the L1-L2 level difference between the two cursors when they are both active. The parameter level being lower than the minimum measurable level is indicated by a series of dashes (- - - - ). Cursors will be disabled pressing the CURSOR key again.

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SPECTRUM MODE (SPECTRUM BY OCTAVE OR THIRD OCTAVE BANDS)

The spectrum analyser operation mode allows the visualisation of frequency spectrum by octave bands from 31.5Hz up to 8kHz and, if the “Third Octave” option is active, also by third octave bands from 25Hz to 12.5kHz. Spectral analysis is carried out and eventually recorded without any frequency weighting (Z) while the spectrum display can be also A or C weighted, for a fast evaluation of spectral components audibility. The spectrum by octave bands or by third octave bands is combined, for possible comparisons, with a wideband level that might be A, C or Z weighted, as programmed.

The average spectrum (AVR) is linearly integrated band by band throughout the integration time (from 1s to 99h) shared with the SLM mode.

If integration is performed in single mode (MENU >> Instrument >> Measurement >> Integration Mode: SINGLE), the instrument will automatically switch into the HOLD mode when reaching the set integration time, allowing to check the result and eventually print or store it. Press HOLD to continue with the display update.

If the continuous recording is activated (pressing at the same time REC and START keys), the integration time will act like a timer, stopping automatically the measurement when Tint is elapsed.

If integration is in multiple mode (MENU >> Instrument >> Measurements >> Integration Mode: MULT), the instrument will automatically reset the levels at the end of the programmed integration time, starting a new integration cycle (see the “DESCRIPTION OF THE DIFFERENT ACQUISITION MODES” on page 29); in this way a multi-spectral analysis is obtained with an acquisition time period from 1s to 1h.

Spectral analysis, normally frequency unweighted (Z), can be carried out applying A or C frequency networks. The A or C frequency weighted analysis is used to evaluate audibility of different spectral components.

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Some parameters can be changed without accessing the menus, but simply using the keys SELECT, the four arrows -UP, DOWN, LEFT and RIGHT- and ENTER: pressing several times the SELECT key, can be selected sequentially the graph vertical scale, the integration time, the spectra frequency weighting A, C or Z and the wideband auxiliary weighting (for more details, see "Selecting Parameters " on page.16).

In this display mode, the Monitor function works as in the SLM mode while the continuous recording function is not available in this display mode. However, if you press REC and hold it down for at least 2 seconds, the spectrum currently displayed can be recorded at any time.

The integration mode and the Auto-Store function change the recording functioning (with the “Data Logger” option) as described in the table below (see the chapter “DESCRIPTION OF THE DIFFERENT ACQUISITION MODES” on page 29).

Integration

Auto-Store: OFF Auto-Store: ON

SINGLE

No recording.

Auto-Store of OCTAVE and, as an option, THIRD OCTAVE (together with SLM) at the end of the programmed integration interval.

MULTIPLE

Auto-Store of OCTAVE and, as an option, THIRD OCTAVE (together with SLM) at intervals equal to the set integration time. At the beginning of each period, integrated levels and spectra are set to zero.

DISPLAY DESCRIPTION

The display upper line shows, after the recording status symbol and the overload indicator, the graph updating mode (AVR), the integration interval (shared with the SLM display mode) and, on the right, the recording time. The values on the left side of the graph are: the full scale, the scale factor and the scale beginning. The amplitude of the vertical scale of the displayed graph corresponds to 5 divisions. The amplitude of each division is called “scale factor” of the graph and appears in the middle of the vertical axis.

Using the RIGHT (zoom +) and LEFT (zoom -) keys, this parameter is selectable in real time among 20dB, 10dB or 5dB by division. Use the UP and DOWN arrows to set the graph full scale with steps equal to the selected scale factor, starting from the instrument full scale2. In this way, the graph can be shifted UP or DOWN according to the pressed key.

A bar on the display right side shows the wideband level, weighted Z, C or A, as selected. The applied frequency weighting is shown under the bar.

In the lower left part of the screen it’s shown the spectrum frequency weighting (Z, C or A).

USING THE CURSORS

To activate cursors on the graph, press CURSOR on the keypad. If you press CURSOR repeatedly, either L1 or L2 cursor, or both ΔL cursors in “tracking” will be activated in succession: the

selected cursor will flash. Use the LEFT and RIGHT arrows on the keypad to move the selected cursor on the graph.

The display second line shows level and central frequency of the filter indicated by the active cursor or the level difference between the two cursors when they are both active.

The instrument full scale is determined by the selection of the input gain by choosing from the menu: MENU >> In-

strument >> Input gain.

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The level is indicated in dB for un-weighted spectra or in dBA or dBC for A and C weighted spectra respectively. In the octave and third octave spectrum mode, cursors can be also positioned on the bar representing the wideband channel. Filters having a level lower than the minimum measurable are indicated by the cursor with a series of dashes (- - - -).

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STATISTICAL GRAPHS

The functioning mode with advanced statistical analyzer allows analyses on the sound pres- sure level with FAST time constant (sampled 8 times per second) or short equivalent level (integrated every 0.125s) or peak level (calculated twice per second) with any frequency weighting (only C or Z fo r peak level).

The statistical analysis is done with 0.5dB classes for sound levels from 21dB to 140dB and provides graphic display of the sound level distribution of probabilities and percentile levels. The graphs can be enabled in Menu >> Statistical Analyzer >> Display Statistics. Disabling the displays does not influence the programmable L1–L4 percentile level calculation.

The following figure shows the level distribution of probabilities on the 6-minute measure- ment of the noise issued by a climatic room. During measurement an acoustic calibrator was switched on for about 2 minutes near the microphone.

The distribution of probabilities shows the different “population” of the examined noise clearly. From lower levels, the first peak (about 63dBA) reflects the room background noise caused by the ventilation system. The second peak (about 65dB) concerns the cooling compressor activation. The third peak (about 69dB) is the tone issued by the calibrator.

In the following figure the cumulative distribution for the same sample above can be seen. The cumulative distribution is built from the 100% of the levels under the measured minimum, and subtracting the probability of each you get 0 for the levels over the measured maximum.

The percentile levels are calculated interpolating the cumulative distribution.

The statistical analyzer resets the classes at the beginning of measurement and it will continue accumulating the statistic until the end of the measurement. When the continuous recording is activated with the single integration mode, the integration time acts like a timer for data acquisition, stopping automatically the measurement when the time is elapsed. When the level integration is

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performed in multiple mode, or report recording is active, the statistical graphs are cleared at the beginning of every interval set.

Statistical analysis is shown with two different graphical screens: the probability distribution and percentile levels graph.

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LEVEL DISTRIBUTION OF PROBABILITIES

Fig. 8 - Description of the distribution of probabilities display

The figure shows the distribution of probabilities of the A weighted equivalent level with a

0.125s sampling interval. The vertical axis shows the sound levels in decibels and the probabilities are on the horizontal axis.

The display shows the sampling interval in the left lower corner, and the chosen measurement parameter for the statistical analysis in the first line on the right of the status indicator and possible overload indicator.

The amplitude of the vertical scale of the displayed graph corresponds to 5 divisions. The amplitude of each division is called “scale factor” of the graph and appears in the middle of the vertical axis. This parameter is selectable in real time among 20dB, 10dB or 5dB by division. These correspond to the 2dB, 1dB or 0.5dB classes in the graph. The scale factor can be set using the RIGHT (zoom +) and LEFT (zoom -) keys. Use the UP and DOWN arrows to set the graph full scale with steps equal to the selected scale factor. In this way, the graph can be shifted UP or DOWN according to the pressed key.

An “analogue” bar indicator on the display right side provides the un-weighted instantaneous level of the input sound pressure level, as for the SLM mode bar.

The parameter chosen for statistical analysis can be changed without accessing the menus, but simply using the SELECT keys, the four arrows UP, DOWN, LEFT and RIGHT and ENTER (for more details, see "Selecting Parameters " on page 16).

Using the Cursors

To activate cursors on the graph, press CURSOR on the keypad. If you press CURSOR repeatedly, either L1 or L2 cursor, or both ΔL cursors in “tracking” will be activated in succession: the selected cursor will flash. Use the LEFT and RIGHT arrows on the keypad to move the selected cursor on the graph. The second line at the top of the display shows the level and central frequency of the class and the relevant probability indicated by the active cursor, or the probability for the levels in the interval between the two cursors when they are both active. Press CURSOR again to disable the cursors.

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PERCENTILE LEVELS GRAPH

The graphic display is available for the sound level distribution of probabilities and also for the percentile levels.

Fig. 9 - Description of the percentile levels display

The figure shows the percentile levels graph corresponding to the distribution of probabilities shown in the above paragraph.

From the sound level distribution of probabilities you can calculate the cumulative distribu- tion of probabilities on the same classes. The cumulative distribution is equal to 100% for the classes with levels under the measured minimum, and 0% for the classes with levels over the measured maximum. From the minimum measured level class, the cumulative distribution decreases for the relevant probability of each class until the class corresponding to the maximum measured level, where it becomes zero. The L1 – L99 percentile levels are calculated interpolating the cumulative distribution of probabilities.

The vertical axis shows the sound levels in decibels and the percentile index is on the horizontal axis. The display shows the sampling interval in the left lower corner, and the chosen measurement parameter for the statistical analysis in the first line, left of the status indicator and the possible overload indicator.

The amplitude of the vertical scale corresponds to 5 divisions. The amplitude of each division is called “scale factor” of the graph and appears in the middle of the vertical axis. This parameter is selectable in real time among 20dB, 10dB or 5dB by division. The scale factor can be set using the RIGHT (zoom +) and LEFT (zoom -) keys. Use the UP and DOWN arrows to set the graph full scale with steps equal to the selected scale factor. In this way, the graph can be shifted UP or DOWN according to the pressed key.

An “analogue” bar indicator on the display right side provides the non-weighted instantaneous level of the input sound pressure level, as for the SLM mode bar. The parameter chosen for statistical analysis can be changed without accessing the menus, but simply using the SELECT keys, the four arrows (UP, DOWN, LEFT and RIGHT) and ENTER (for more details, see "Selecting Parameters " on page 16 ).

Using the Cursors

The CURSOR, LEFT and RIGHT keys on the keypad enable and move the cursor. The second line at the top of the display shows the percentile level indicated by the cursor. Press CURSOR again to disable the cursor.

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EVENT TRIGGER FUNCTION

The Event trigger function can be enabled only with the single integration mode. During measurement this function can be used to isolate a sound event identifiable by sound level variation or by synchronization to an external signal or, manually, by pressing a key.

The noise descriptor used by the trigger function is selected in the PROFILE view (Menu >> Trigger >> Source: LEV). The level variation that triggers the event can be positive or negative (Menu >> Trigger >> Trigger Polarity) and the trigger threshold (Menu >> Trigger >> Trigger Threshold and Menu >> Trigger >> Bottom Threshold) can be different from the deactivation threshold (Menu >> Trigger >> Trigger Threshold and Menu >> Trigger >> Bottom Threshold). The following figure shows an example of a positive polarity sound event capture. The sound level (LAF) exceeds the trigger threshold for time T0 and, later, the bottom threshold for time T2.

Fig. 10 - Description of the event Description of the event

To prevent short duration pulses being detected as sound events, a minimum trigger duration can be set up to a maximum of 10s (Menu >> Trigger >> Minimum Duration). If the threshold is exceeded for less than the set time, the event is neglected. Also a minimum deactivation duration can be set: when the deactivation threshold is exceeded, the event close is delayed for the set time, up to a maximum of 255s (Menu >> Trigger >> Stop Delay).

In the example shown in the picture, since the trigger conditions exceed the minimum duration, that is they persist at least for time T1, the event levels integration begins, including the 2 seconds before the threshold is reached (pre-trigger). This pre-trigger time cannot be modified. The event levels integration ends at time T3, that is, after the stop delay from the T2 time corresponding to the bottom threshold being reached.

The event trigger feature can be activate also by pressing the ENTER key (Menu >> Trigger >> Source: MAN). In this case the minimum duration parameter has no effect and the event begins as soon as the trigger is detected.

For each identified event, the HD2010UC/A calculates the following:

• 5 programmable selectable parameters: maximum and minimum levels, peak level, equiva-

lent level and SEL

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• Average spectrum by octave and, if installed, one-third octave bands

• Full statistical analysis

These parameters are not displayed but can be stored, completely or partially, at the end of each level. The menu Recording >> Event allows selection of the 5 parameters and memorization. The event parameters integration begins 2 seconds before triggering. This pre-trigger time cannot be modified. A special printing function, synchronized with the trigger, is available for communication of the event itself via RS232 (Menu >> Trigger >> Print).

If the trigger is enabled, the sound level profile is displayed with black background when the

trigger is not active so as to highlight the event’s portion.

Fig. 11 - Description of the “Event trigger” display

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DESCRIPTION OF THE DIFFERENT ACQUISITION MODES

The HD2010 makes measurements according to two different acquisition modes either single (standard for HD2010UC/A) or multiple. The single integration begins by resetting the integrated levels (e.g. the Leq) and ends when the set integration time Tint is elapsed or when the acquisition is manually interrupted by the RUN/STOP key. The following figure shows the Leq Short profile calculated twice per second and the integrated Leq over a measurement time of 1 minute in single mode.

In the measurement time span, the Leq Short (LAeqS) shows three phases with high noise, about 80dB, and a variable 52-60dB background noise. The Leq profile shows that the integration of the three high noise phases gives an equivalent level stabilizing at about 77dB at the end. It is often necessary, or convenient, to divide the measurement time in equal duration intervals and calculate the integrated levels, as Leq, maximum and minimum levels, etc. on each interval separately instead of on the entire measurement. The multiple integration mode serves this purpose.

The multiple integration divides the measurement in equal intervals according to the set integration time(Tint). Each single interval begins by resetting the levels and ends when the set integration time is elapsed; the integration levels sequence ends when manually interrupted by the RUN/STOP key. The following figure shows the Leq Short profile calculated twice per second and the integrated Leq over intervals of 20s during a measurement time of 1 minute in multiple mode.

The Leq Short profile is similar to that of the previous figure. The Leq Short profile shows the multiple integration mode divided the measurement time three intervals of 20 seconds, each isolating the three noise phases. Some markers point out the beginning of each interval, when the Leq was reset. Three equivalent levels at about 75dB are obtained, corresponding to each interval. To select the integration mode select the proper parameter (MENU >> Instrument >> Measurement >> Integration Mode) as SING for single integration or MULT for multiple integration. To perform the setting directly from the keyboard, press SELECT to choose the integration interval. When the integration interval numeric value flashes, press RIGHT to set the multiple integration mode or LEFT to set the single integration mode. When the integration mode is set on MULT, the “Tint” symbol flashes.

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SINGLE INTEGRATION

When the integration mode is single, the sound level meter, after clearing the integrated levels (i.e. Leq), starts measuring the instantaneous sound levels (i.e. SPL) and calculating the integrated levels regularly until acquisition stops.

This mode provides, at the end of the measurement session, the integrated levels over the whole acquisition period. The parameter “MENU >> Instrument >> Measurement >> Integration Interval” allows to suspend the display update, when set time is over.

Now, to store displayed data press REC and hold it down for at least 2 seconds, then select the manual storage option. Press PRINT if you want to send displayed data to the serial output.

While display update is stopped in HOLD, the sound level meter continues measuring and calculating the sound levels; press HOLD to let display update start again. If you do not wish to continue beyond the set integration time, press STOP to interrupt the acquisition. When the integrating mode is SINGLE and continuous noise level recording is active, the acquisition is automatically stopped once the set integration time is elapsed.

The PAUSE/CONTINUE key can be used to suspend the calculation of integrated levels temporarily, while instant levels are still being measured. During a pause, and as far as the integrated levels displayed on the SLM page are concerned, you can delete the last integration seconds through the “BACK-ERASE FUNCTION (DATA EXCLUSION)” see page 16. The monitor function is not affected by the acquisition pauses. The continuous recording function suspends data storage during the acquisition pauses and automatically stores a marker indicating the pause duration and the possible use of the erase function.

The sound level meter has a further timer for interval acquisition (MENU >> Instrument >> Measurement >> Report Time). This parameter can be used to break up the measurement time into programmable duration intervals from 1 second to one hour, and calculate a set of 5 selected integrated levels for each interval, namely Leq, maximum and minimum levels, SEL, and statistical levels. The average spectrum (AVR) for each interval can also be calculated by both octave band and third octave band, and using statistical analysis (MENU >> Recording >> Report). These data cannot be displayed directly but can be recorded by enabling continuous recording. The report levels can be displayed by loading the recording from the sound level meter memory using the Navigator, and selecting the Report mode for the replay. The interval acquisition can be enabled only in single integration mode.

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MULTIPLE INTEGRATION

When the integration mode is at intervals, the sound level meter automatically makes a continuous sequence of acquisition intervals having a duration equal to the integration time set through the parameter “MENU >> Instrument >> Measurements >> Integration interval”. Each acquisition interval starts clearing the integrated levels and the “Tint” symbol on the SLM page flashes.

This integration mode, together with the Auto-Store function (MENU >> Instrument >> Recording >> Auto-Store), allows to record at a programmable rate the SLM parameters together with the octave and third octave (as an option) band spectra (see “THE RECORD FUNCTION” on page

34). Automatic recording occurs at the end of each integration interval.

When the Auto-Store function is active, the REC symbol will flash alternating with the indicator of the sound level meter acquisition, up on the left side of display.

The multiple integration excludes the possibility of using the Report Time parameter to record using intervals and the event trigger. The statistical analysis and the other integrated levels are cleared at the beginning of every integration period.

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The following table gives the different measurement and storage modes of the HD2010UC/A.

Integration Auto-Store Measurements Continuous Recording Single Recording

SINGLE

OFF

Press

to start.

The integration ends when t=T.Int., enters in HOLD mode, and it is possible to continue by pressing HOLD

or to stop with

Press + to start.

Automatic stop when t = T.Int.

Press to record the

displayed data.

Press

to start.

Automatic stop when t=T.Int. with recording of the SLM, OCTAVE and T.OCTAVE screens.

---- ----

MULTIPLE

OFF

Press to start.

The integration of the sound levels occurs according to intervals equal to T.Int. The integrated levels are cleared at the beginning of every interval.

Press + to start.

Continuous recording with LAST marker at the end of each integration period. Stop

by pressing

Press

to record the

displayed data.

Press

to start.

The integration of the sound levels occurs according to intervals equal to T.Int. The integrated levels are cleared at the beginning of every interval and recorded at the end.

---- ----

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PRINT AND MONITOR FUNCTIONS

If you press and soon release the PRINT key, you can send to a PC or to a printer, via serial interface, the screen-page displayed when pressing the key, in ASCII format. The suggested printer is model HD40.1 (see page 87). On the instrument display, a letter

“P”, replacing the status indicator, highlights data transfer. If the PRINT key is hold down until the letter M (Monitor function) and the recording status indicator flash alternatively, the displayed screen will be continuously sent to the serial interface: press PRINT again or STOP to end the operation.

After activating the Monitor function, even if you press the MODE key, the type of screen

sent to the serial interface will not change.

The PRINT function can also be selected starting from the STOP status. In this case the func-

tion will automatically activate as soon as the instrument switches into the RUN mode.

If the instrument gets into the PAUSE mode, the function will remain active, but sent data will be combined with the “P” symbol indicating the suspension status of the integrated parameter calculation.

The Monitor function does not interfere with data recording on memory and can be activated simultaneously. A series of values is sent every 0.5s.

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THE RECORD FUNCTION

The REC key supervises the function of recording data on the instrument memory. Two recording modes are available: single (manual or automatic) and continuous recording.

MANUAL AND AUTOMATIC SINGLE RECORDING

When only the REC key is pressed for at least 2 seconds, the displayed screen will be recorded as a single record. When you press REC and before the instrument stores the active screen, you will be asked to confirm the recording title containing order date and number. This operation can be performed in RUN, HOLD, PAUSE and STOP modes. When the single recording is activated while the instrument is in STOP mode, you will be first asked to choose between automatic and manual storage.

If the manual recording has been selected, it will happen what described above (single re-

cord recording).

If, on the contrary, the automatic “AUTO” recording mode has been selected, the sound level meter is set for Auto-Store recording. The parameter “MENU >> Data logger >> Measurement >> Auto-Store” will be activated and the REC symbol blinks over the status indicator.

Press START to begin automatic recording: as soon as the measurement time reaches the set integration time, the parameters shown on the SLM screen and the spectra by octave and third octave bands (with the “Third Octave” option) are recorded automatically.

If the integration mode is single, the acquisition will be stopped. If it is multiple, a new integration and recording cycle will start automatically after all parameters are reset.

Press REC while the instrument is in STOP mode, to disable the Auto-Store function and jump back to the continuous integration mode.

The automatic recording can be also activated from the corresponding menu item (MENU >> Data Logger >> Measurement >> Auto-Store).

If the function Auto-Store is activated in single integration mode, the parameters displayed in the SLM mode will be stored together with the spectrum both for octave bands and, with option, for third of octave bands, once the set integration time expire. The logging will be automatically stopped.

When parameter “MENU >> Instrument >> Measurement >> Int.mode” is set in MULT mode (the “Tint” symbol blinks in the SLM screen), the acquisition is repeated on time intervals

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equal to the integration time set; each interval is preceded by the reset of integrated levels (see chapter “DESCRIPTION OF THE DIFFERENT ACQUISITION MODES” on page 29).

This integrating mode, combined with Auto-Store function, enables to record on a time basis equal to integration time Tint set, parameters shown on the SLM mode display together with spectrum both in octave and, if option is installed, in third octave bands. Integration time (that corresponds to recording interval) can be set directly from SLM screen or using the specific menu parameter (MENU >> Instrument >> Measurements >> Integration time).

CONTINUOUS RECORDING

Pressing both REC and START/STOP/RESET keys starts the continuous data recording on memory. The 3 parameters of SLM mode are stored twice per second, while the A weighted sound level with FAST time constant is stored 8 times per second.

Press PAUSE to stop recording temporarily; press CONTINUE to restart it. As soon as you go back to the RUN status, a special record is stored, containing indications about the possible erase (see the “Back-Erase Function” in SLM mode on page 16) besides date and time.

The HOLD key does not affect data recording.

When the continuous recording is active, if the integration mode is set to single, the integration time acts like a timer stopping automatically the acquisition as soon as the set time is elapsed. Integration time is programmable from SLM display or using the relative menu item (Menu >> Instrument >> Measurement >> Integration interval).

When integration mode is set to multiple, continuous recording do not stop when integration time elapses: a special marker (“Last”) is stored together with the last data just before the integrated levels clearing at the beginning of each integration period (see the chapter “DESCRIPTION OF THE DIFFERENT ACQUISITION MODES” at page 29). The spectra are cleared in addition to the statistical levels and the integrated parameters displayed on the SLM screen.

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CONTINUOUS RECORDING OF REPORTS AND EVENTS GROUPS

Performing the measurements in single integration mode, you can also record reports and events, together with the sound level profiles. The parameters of the SLM and PROFILE screens are included in the Measurement group. Together with the Measurement group recording, you can also enable the Report and Event groups recording. The Report and Event groups are composed of the following storable parameters:

• 5 integrated parameters

• Average spectra for octave and third octave band (with “Third Octave” option”)

• Statistics

The Report group is recorded at programmable intervals, using the parameter MENU >> Instrument >> Measurement >> Report Time, from a minimum of 1s to a maximum of 1 hour. The 5 integrated parameters, the spectra and the statistics are automatically cleared at the beginning of every report time. The 5 reported parameters can include:

• FAST, SLOW and IMPULSE time weighted maximum and minimum levels

• Peak level

• Equivalent sound pressure level

• SEL

• Preset percentile levels L1, L2, L3 and L4

The enabling of the report time is an alternative to the multiple integration mode. The report time can be set only in single integration mode.

The Event group is recorded, per each detected event (see paragraph “EVENT TRIGGER FUNCTION” on page 27), at the end of the event itself. The 5 integrated parameters, the spectra and the statistics are automatically cleared at the beginning, and are integrated for the entire duration of the event. The 5 event parameters can include:

• FAST, SLOW and IMPULSE time weighted maximum and minimum levels

• Peak level

• Equivalent sound pressure level

• SEL

The event trigger feature can be activated only in single integration mode. Therefore it is not possible to enable event recording while multiple integration mode is selected.

When the Measurement group recording is activated together with the Report and Event groups recording, the Measurement group continuous recording is enabled only with the events sensed by the event trigger. This allows a lot of memory to be saved, minimizing information losses: during the events the maximum quantity of logged information occurs, while with outside sound events, the recording of the level is also carried out according to a reduced time resolution, as defined in MENU >> Instrument >> Measurement >> Report time. Fig. 12 shows the recording flow for the Report and Event groups.

The Measurement group recording interval is equal to 2 recordings per second. In the following example, also the Report group items are memorized with a Report time amounting to 10s.

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Fig. 12

When the trigger function detects an event, identified by the overcoming of the trigger threshold, or when ENTER is pressed, a time marker is recorded.

Similarly, when the end of event conditions are sensed, as identified by the deactivation threshold being reached, or by the external TRGIN signal, or when ENTER is pressed, and after the set stop delay has elapsed, another time marker is recorded. After the time marker, when the event is closed, the record containing the Event group information is logged.

When the event trigger uses the Profile view sound level as source (Menu >> Trigger >> Source: LEV), the event data are recorded only when the trigger threshold (Menu >> Trigger >> Trigger Threshold) exceeds the minimum duration time (Menu >> Trigger >> Minimum Duration).

The following figure shows the recording flow for the Measurement, Report and Event groups. The Measurement group recording is enable only during the event; outside the events, only Reports are recorded. In the following example a report is recorded every 10s.

Fig. 13 - Recording flow for the Measurement, Report and Event groups

When the trigger threshold is exceeded for a shorter period than the minimum duration time, the record containing the Event group information is not logged.

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Delayed acquisition timer

A timer is available to enable data acquisition according to a programmable delay of up to 99 hours. To perform an acquisition with delayed start, the recording parameters need to be set first and then the delayed acquisition timer programmed in the parameter Menu >> Sequencer >> Timer. After programming the sound level meter, you only need to press the REC and RUN keys together (as if starting a logged measurement): confirm with the “YES” key. The instrument switches into stand-by and turns off (see. Fig. 14).

Fig. 14 - Delayed acquisition timer warning screen

The instrument will turn back about one minute before the set delay, to allow execution of the warm up time before starting the automatic acquisition. During this waiting minute, the “TIMER” message blinks, showing the automatic acquisition feature has been activated.

Fig. 15 - Waiting for the timer to start

The acquisition will end when the set integration time (Tint) has elapsed and the instrument will automatically turn off after disabling the timer.

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DESCRIPTION OF THE MENU FUNCTIONS

The menu collects all of the parameters through which the instrument functions are set. The menu can be accessed even when the instrument is measuring, but parameters can be modified only if the instrument is in STOP mode. If this is not the case, a message will invite you to stop the current measurement: “WARNING! Stop the measurement to continue".

SELECT PARAMETER

WARNING!

Stop measurement

to continue.

YES NO

Press YES, and you will be allowed to change the selected parameter.

Some of the parameters listed in the menu can also be modified directly from the measurement displays: see the chapter concerning the different display modes (from page 12 onwards).

The menu is nest-structured, that is, it is organised in menus and submenus. To select a menu item, use the UP and DOWN arrows until the selected item flashes. When the parameter next to a menu item does not flash, it means that the item cannot be changed.

This parameter can be changed

This parameter CANNOT be changed

Press SELECT to access the selected submenu or to modify the selected parameter. Use the UP and DOWN arrows to edit the flashing selected parameter: press ENTER to confirm the new value, press MENU to cancel the input changes.

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Press MENU to exit a menu and return to the upper level until you get the measurement display again.

When you access the menus, current date and time are displayed, as well as the battery charge level and the available memory. If you are in a submenu, the "SELECT MENU" item becomes "SELECT SUB-MENU". The dots at the end of a list mean that there are other items following the visible ones: press the DOWN arrow to display them.

INSTRUMENT

The Instrument menu includes all data relevant to the instrument identification, as well as some general parameters of the instrument itself, input and output settings and measurement global parameters. It consists of four submenus, as described below.

IDENTIFICATION

It includes the information that identify the instrument and the microphone. These are all items that cannot be changed by the user.

• Instrument: instrument name.

• Serial N.: instrument serial number.

• Version: current firmware version loaded.

• Microphone: free field microphone UC52 is the standard supplied.

• Mic. S.N.: microphone serial number.

• Mic. Response: type of microphone response. FF stands for Free Field, DF for Diffused

Field.

• Class IEC61672: Class of tolerance according to IEC61672:2002.

• Memory: memory available on the instrument.

• Options: firmware options.

• Ext. range: Off.

SYSTEM

It allows configuring some system parameters.

• Time: current time.

• Date: current date expressed as year/month/day.

• Display contrast: allows adjusting the display contrast. When the ambient temperature

changes, the display contrast slightly changes: it can be adjusted entering a higher value to in-

crease the contrast or a lower one to decrease it. The value can be set between 3 (minimum)

and 9 (maximum).

HD2010UC/A - 41 - V4.1

• Auto-Power-Off: the instrument is provided with the auto-power-off function that automati-

cally switches it off after 5 minutes if it is in STOP mode and no key has been pressed. Before

switching off, the instrument will make a series of beep: press any key to prevent the instru-

ment shutting off. The function is active if this menu item is "ON". If you set Auto-Power-Off

= OFF, the instrument will not automatically shut off. In this case the battery symbol will

flash even if batteries are fully charged.

INPUT OUTPUT

Submenu for the choice of parameters relevant to the instrument inputs and outputs.

• Baud Rate: this parameter and the next ones define the properties of the serial connection.

Selectable baud rate values go from a minimum of 300 to a maximum of 230400 baud. The

higher is the value, the faster is the connection; therefore, when possible, it is suggested to se-

lect the highest available value to speed up data transfer as much as possible. If the instrument

is connected to a printer with RS232 serial input or with a serial/parallel converter, the value

to be set is the one provided by the printer manufacturer.

WARNING: When you use the serial interface, the communication between instrument

and computer (or printer with serial input) works only if the instrument and PC (or de-

vice) baud rates are the same. Take care of this note when using data transfer programs

requiring a manual configuration of the serial port parameters, such as, i.e. Hyper-

Terminal. The Noise Studio program, combined with the HD2010UC/A, automatically

sets the serial port, so that no action by the operator is required.

• RS232 Bits: (non-modifiable parameter) number of bits of which transferred data are made

up, the value is 8.

• RS232 Stop Bits: (non-modifiable parameter) stop bit, the value is 2.

• RS232 Parity: (non-modifiable parameter) parity bit, the value is: none (OFF).

• Serial Device: identifies the device connected to the serial port.

The connection possibilities are:

 PRINTER: connection to a printer with RS232 input  RS232: connection to a PC equipped with RS232 port (physical)  MODEM: connection to a modem with RS232 input (see Connection to a modem

on page 86)

 USB: connection to a PC by USB port (see “CONNECTION TO A PC WITH

USB INTERFACE” on page 88).

 MC connection to HD2010MC optional module for data recording on Secure

Digital memory card (see specific chapter on page 91)

MEASUREMENTS

The Measurement item includes the acquisition general parameters.

• Input Gain: with Input Gain = 0 the measuring range upper limit equals 140dB, and as much

as the input gain increases the maximum measurable level decreases correspondingly (see

page.94). Select the proper gain according to the level of sound to be measured.

• Quick Sampling: integration period used to measure reverberation time.

• Integration interval: Once this time has been reached, the instrument automatically switches

to HOLD, interrupting display update. It can be set from a minimum of 1s to a maximum of

99 hours. When continuous recording is activated, the integration time acts like a timer for

data acquisition, stopping automatically the measurement when the time is elapsed. If set to

0s, the timer is disabled and the integration becomes continuous.

• Report Time: report parameters are integrated over intervals corresponding to the set time.

At the beginning of every interval report parameters are automatically cleared. Report time

HD2010UC/A - 42 - V4.1

can be set to: 1, 2, 5, 10, 20 and 30 seconds, 1, 2, 5, 10, 20, 30 minutes and 1 hour. A report

time can be set only for the single integration mode (see parameter “Integration mode”). This

parameter needs the “Advanced Analyzer” option”.

• Max Back-Erase: maximum erase interval of data recorded in SLM mode. The available val-

ues are: 5s, 10s, 30s and 60s: the erase interval is settable with 1s, 2s, 5s or 10s steps, respec-

tively. See description on page.16.

• Exchange Rate: is used together with "DOSE Threshold" and "DOSE Criterion" in DOSE

calculation. It represents the variation of the sound pressure level corresponding to the double

or the half of the exposure maximum time with the same Criterion Level (indicated as “DOSE

Criterion”). Its value can be equal to 3dB, 4dB or 5dB.

• DOSE Threshold: it is the noise level below which the DOSE is not increased. The value can

be set in the 0dB÷140dB interval, with 1dB steps.

• DOSE Criterion: it is the noise level providing a DOSE equal to 100% after an 8 hour expo-

sure. The value can be set in the 60dB÷140dB interval, with 1dB steps.

• Overload Level: if the sound level exceeds of more than 1 dB the upper limit of the measur-

ing range, set according to the selected input gain, the display will highlight the overload in-

dication (Δ and Λ). The indication can be activated also at lower input levels, programming

this parameter from 20dB, minimum, to 200dB maximum, with 1dB steps. The shown level

defines the overload threshold when the input gain corresponds to 0dB (Input Gain). The

overload threshold automatically scales with the input gain.

• Integration mode: Two integration modes are available: the former is single (SING) and the

lat ter is multiple (MULT). For the descr iption of these modes see “DESCRIPTION OF THE

DIFFERENT ACQUISITION MODES” on page 29. The multiple integration mode requires

an Integration interval different from zero be set, and disables Report Time and Event Trig-

ger.

• Lev. 1, 2, 3 and 4 Percentile: in the statistical analysis of sound events, LN percentile levels

are defined as the levels of noise exceeded for N time percentage throughout the whole meas-

urement interval. For example, L1 represents the sound level exceeded by 1% of the meas-

urement time. These items define 4 percentile levels selectable between 1% and 99% with 1%

steps. The corresponding variables are shown in the SLM view as L1, L2, L3 and L4, com-

bined with the respective percentage.

SOUND LEVEL METER

The Sound Level Meter menu features all parameters relevant to the SLM display mode. These items can be changed directly from the respective display as described in "Selecting Parameters " on page 16. The first three items of the menu, from Par. 1 to Par. 3, define the three measuring parameters and the respective frequency weightings relative to the SLM display mode. Press RIGHT to change the time weighting of measuring parameters, when selected. When the time weighting flashes, use the UP and DOWN arrows to change it. The list of available descriptors is shown on appendix A1 on page 121.

SPECTRUM ANALYZER

The Spectrum Analyser menu includes the specific parameters relative to spectra display modes. These items can be changed directly in their screens.

• Aux Pond.: the frequency weighting of the wideband channel combined with the spectrum

and displayed with a vertical bar on the right of the spectrum. A, C and Z weightings are

available.

HD2010UC/A - 43 - V4.1

• Frequency spectrum weighting: spectrum can be un-weighted (Z) or C or A weighted

(stored spectrum is always LIN)

• Octave Display: enables (ON) or disables (OFF) displaying of octave band spectra. This pa-

rameter needs the “Advanced Analyzer” option.

• T. Octave Display: enables (ON) or disables (OFF) displaying of third-octave band spectra

(“Third octave” option required).

STATISTICAL ANALYZER

The Statistical Analyzer menu collects the specific parameters related to the statistical graphs display modes. These items can be changed directly in their screens.

• Param.: the parameter used for selected statistical calculations: LFp, Leq and Lpk with A, C

and Z (only C and Z for Lpk) weightings. The sampling frequency is equal to 8 samples/s

(only 2 samples/s for L

• Class width: statistical analysis is performed by 0.5dB classes.

• Display Stat.: enables (ON) or disables (OFF) displaying of the distribution of probabilities

and percentile levels graph.

TRIGGER

The Trigger menu collects the specific parameters related to the event trigger.

• Source: the trigger source can be chosen among: profile view sound level (LEV) or pressing

ENTER key (MAN).

• Trigger Threshold: the trigger threshold on the profile view sound level (LEV); it can by

programmed with 1dB steps.

• Bottom Threshold: the deactivation threshold, different than the trigger one, on the profile

view sound level (LEV); it can by programmed with 1dB steps.

• Trigger Polarity: it is possible to choose increasing (POS) or decreasing (NEG) levels for the

trigger on the profile view sound level (LEV). For the increasing levels trigger, the Trigger

Threshold will be higher than the Bottom Threshold, for the decreasing levels trigger the

Trigger Threshold will be lower than the Bottom Threshold.

• Minimum Duration: a duration filter is available to eliminate false triggers. It is activated

upon detection of the event, only if the trigger condition persists for a number of seconds at

least equal to this parameter. It is used only if the Source parameter is set to LEV.

• Stop Delay: when the trigger conditions are not present anymore, the event ends after a num-

ber of second equal to this parameter has elapsed.

• Printing: printing of a warning string (TAG) can be enabled through the serial interface for

each event.

RECORDING

In the Recording menu the parameters relating to the logging of the measured data can be found. It collects the settings concerning the recording of the sound levels measured in each screen, the report, and event parameters. If no parameter is enabled for recording (all OFF), the instrument warns of the impossibility to record. The recording parameters are divided in three sub-menus: Measurement, Report, and Event.

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MEASUREMENTS

In this menu continuous recording is defined, as described in THE RECORD FUNCTION on page 34.

• Auto-Store: activates the auto-recording mode of SLM, OCTAVE and THIRD OCTAVE

screens, as described in THE RECORD FUNCTION on page 34. By enabling this feature report time and event trigger are disabled.

• SLM + PROFILE: activates the continuous recording of parameters of the SLM screen and

PROFILE.

If the Auto-Store function is activated, SLM and spectra screens will be automatically stored when the set integration time is over. When this function is activated with the multiple integration mode, recording is performed automatically according to the set integration time. Integration time is programmable from SLM display or using the relative menu item (Menu >> Instrument >> Measurement >> Integration interval). The enabling of the recording mode is indicated by a flashing REC over the status indicator. Recording is started by pressing RUN. To disable the Auto-Store function press the REC key briefly.

REPORT

In this menu the recording of the reports is defined, as described in the paragraph CONTINUOUS RECORDING OF REPORTS AND EVENTS GROUPS. Each item can be enabled separately, as with the measurement recording. In order to avoid occupying memory space uselessly, we recommend to enable only the needed items and set the others to OFF. The integration interval (recording time) of the reports is programmable using the relative menu item (Menu >> Instrument >> Measurement >> Report Time).

• Par.1 – Par.5: define five integrated parameters, with relevant frequency weightings.

• Parameters: enables recording of the 5 parameters Par.1 – Par.5, defined previously.

• Oct. Spectrum: activates the recording of average spectrum (AVR) by octave band.

• T. Oct. Spectrum.: activates the recording of average spectrum (AVR) by third octave band.

• Statistics: activates the recording of the statistics

EVENT

In this menu the recording of the event reports is defined, as described in the paragraph CONTINUOUS RECORDING OF REPORTS AND EVENTS GROUPS. Each item can be enabled separately, as with the measurement recording. In order to avoid occupying memory space uselessly, we recommend to enable only the needed items and set the others to OFF.

• Par.1 – Par.5: define five integrated event parameters, with relevant frequency weightings.

• Parameters: enables recording of the 5 parameters Par.1 – Par.5, defined previously.

• Oct. Spectrum: activates the recording of average spectrum (AVR) by octave band.

• Third Oct. Spectrum: activates the recording of average spectrum (AVR) by third octave

bands (it requires the “Third Octave” option”).

• Statistics: activates the recording of the event statistics

CALIBRATION

• Calibration Level: Sound level of the reference sound source used for the sound level meter

calibration. Allowed values vary from 90.0dB to 130.0dB with a 0.1dB resolution.

• Microphone Response: allows selecting the type of frequency response of the microphone

according to the sound field. The standard setting for the microphone (UC52) is “Free Field”

HD2010UC/A - 45 - V4.1

(FF), since it has a frequency response optimized for the “free field”. Set the parameter to “Random Incidence” (RI) to activate the correction for sound random incidence. This setting is necessary to carry out measurements according to ANSI standards. La The random incidence correction is not available on the HD2010UC/A type 2. When HD WME outdoor microphone protection is used, the right setting for the measurement of aircrafts noise (0°) is FF, while for community noise coming from the ground (90°) the correction to apply is RI.

• Screen correction: it allows to correct the sound level meter frequency response when the

windshield HD SAV, supplied with the instrument, or the outdoor protection HD WME are installed. When this parameter is set on SAV or WME, the sound level meter frequency response is corrected for the presence of the windscreen or the outdoor microphone protection respectively. The correction for the windscreen is not available for HD2010UC/A type 2. For additional details on the correction to be applied, please see the UC52 microphone specific manual.

SEQUENCER

• Timer: programmable acquisition delay in seconds, minutes, or hours up to a maximum of 99

hours (see paragraph Delayed acquisition timer on page 38).

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PROGRAMS

The item PROGRAMS (PROG key) includes the following functions:

• display of the stored data (NAVIGATOR)

• electric and acoustic calibration (ELECTRIC CALIBRATION and ACOUSTIC CALIBRA-

TION)

• diagnostic test of instrument (DIAGNOSTIC CHECK)

• reverberation time measurement (REVERBERATION TIME) – optional program

• Data download on MC: this program allows to copy measurement data stored on the sound

level meter’s flash memory to a Secure Digital external memory card (please see chapter

HD2010MC MEMORY CARD READER on page 91) Each program is here below described in detail.

NAVIGATOR

This program, allows to access data stored on the instrument memory, display and print them, with no need to download them to a PC. It works both with single session data and with multiple ones). Press: PROG >> Navigator >> SELECT to access it. The following screen will appear:

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EXIT CLEAR SELECT

If you press CLEAR, the content of the instrument memory will be cleared. The user will be asked a confirmation before clearing. Press SEARCH to access the first session of stored data (data on memory).

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Batt 95% Mem 92.5%

EXIT LOAD NEXT

The following data are indicated for each file: the type (single, multiple, automatic or reverberation), the progressive number given by the instrument upon logging and the date. Press NEXT to jump to the next file, press LOAD to download the current file. If you press LOAD, the instrument goes back to standard display and the STOP and battery symbols alternate with the R (Replay) and P (Program) letters respectively.

56.9

60.8

79.3

110

01:08:25

Tint= s

LFp

Leq

Lpk

dBA

dBC

The types of files recorded are four:

• Sing. Single screen in manual recording

• Auto SLM, OCTAVE and THIRD OCTAVE (if option is installed) screens in automatic re-

cording

• Mult. Multiple screens in continuous recording

• RT Reverberation measurements (with the option “Reverberation Time”)

File type: “Auto”

Press START to see the data session: the screens of the measurement session will be displayed as per the acquisition order. During the replay, the display mode can be changed jumping from a screen page to another, press PAUSE/CONTINUE to interrupt and re-start the on-screen reproduction or press STOP to finish it. At the end, the instrument will position on STOP. A single screen page can be sent at any moment to the serial interface. While the replay is in pause, press START if you want to display the next data. If, while in pause, the START key is hold down, the replay will be forwarded fast.

File type “Mult.”

Press START to see the data session: if no reports and/or events were recorded, the measurement session screens will be displayed, as for the “Auto” files. If, in addition to measurements, reports and/or events were also recorded, an intermediate page is displayed allowing the display of meas-

HD2010UC/A - 48 - V4.1

ures, reports, or events to be chosen (see paragraph CONTINUOUS RECORDING OF REPORTS AND EVENTS GROUPS on page 36 ). When you replay the reports or events, in SLM view, the report and event parameters are respectively displayed. When you display the events, they are displayed individually with a pause between one and the next. During the pause, START allows the next event to be reloaded and PAUSE to restart the replay. The replay of measurements associated with event recording, automatically enables the pauses at the beginning and end of each event trigger. These pauses correspond to the time markers recorded when the trigger spots the event and at the end when saving the relevant data. If the recording contains measurements, reports, and events, the measurements are not registered continuously but only in coincidence of the sound events detected (see EVENT TRIGGER FUNCTION on page. 27). Disabling of measurements outside the events, in combination with event and report recording, allows two different recording speeds to be maintained, slow and fast, associated with reports and measurements respectively. The maximum recording resolution is used only during events by enabling the Measurement group parameters recording (see CONTINUOUS RECORDING OF REPORTS AND EVENTS GROUPS on page 36) while for the other acquisition elements only the Report group parameters are recorded, using a lower time resolution. When the simultaneous recording of measurements, reports, and events is enabled, and the event trigger uses the Profile view sound level as source (Menu >> Trigger >> Source: LEV), the measurement recording begins as soon as the sound level exceeds the trigger threshold (Menu >> Trigger >> Trigger Threshold) without waiting for the minimum duration time (Menu >> Trigger >> Minimum Duration). The measurement recording ends as soon as the stop delay has elapsed (Menu >> Trigger >> Stop Delay) after the level exceeded the deactivation threshold (Menu >> Trigger >> Bottom Threshold).

File type: “Sing.” and “RT”

The relevant data are loaded and displayed automatically. “RT” files require a few seconds for the data processing required for display.

After having examined a file size, press PROG to jump back to the Memory Navigator menu: press LOAD to reload the current session, NEXT to display the properties of the next session or EXIT to quit. At the end of the list of stored files, “End of Dump” will be displayed. Press REWIND to go back to the first file of the list.

HD2010UC/A - 49 - V4.1

CALIBRATION

Calibration is periodically carried out to ensure the validity of measurements performed by the sound level meter and to control possible long-term drifts of the measuring chain microphonepreamplifier-instrument.

The HD2010UC/A sound level meter stores all calibration typical parameters with respective

date and time in a reserved area. Calibration types can be:

• Acoustic calibration by means of a 1kHz sound level generator, like HD2020

• Electric calibration (Capacitive Transducer Calibration) with the possibility to measure the fre-

quency response of the whole measurement chain, microphone included, using the built-in signal generator.

Calibration is necessary every time that the calibrator level, measured by the sound level meter, deviates from the nominal value for more than 0.5dB.

The acoustic calibration includes the capacitive transducer one and, before carrying it out, it is suggested to ensure that the environment where you are operating is suitable: no sudden sounds, no vibrations on the surface where the instrument is placed, instrument thermal stability.

The electric calibration allows a quick inspection of the electric parameters of microphone and instrument. The calibration procedure includes the inspection of the microphone polarization.

Calibration programs are in the “PROGRAMS” menu, accessible through the PROG key.

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60.8

79.3

110

01:08:25

Tint= s

LFp

Leq

Lpk

dBA

dBC

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SELECT PROGRAM

Memory Navigator Electric Calibration Acoustic Calibration Frequency Response ... Diagnostic Check

Use the UP and DOWN arrows to select the calibration to be carried out:

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SELECT PROGRAM

Electric Calibration

Acoustic Calibration

Frequency Response Diagnostic Check

Fig. 16

when you press SELECT, the calibration display will appear.

HD2010UC/A - 50 - V4.1

The screen shows date and time of the last calibration and the calibrator sound level according to the configuration of the respective parameter (MENU >> Calibration >> Calibr.Level). Answering positively to the request to continue, the selected calibration program will start.

Calibration procedures are carried out in automatic mode and the operator is guided by the onscreen instructions. The calibration result is displayed when the procedure is over and you can choose whether to confirm it or not. If confirmed, the new calibration will be stored.

In order to grant the highest measuring accuracy when the wind shield is mounted, select “Wind Shield Correction” from the CALIBRATION menu to apply a correction to the sound level meter frequency response and compensate the effects of the HD SAV shield provided with the instrument. All measurement parameters with wideband frequency weightings and with constant percentage bandwidths, either octave or third octave, are automatically adjusted.

Besides the windshield correction, the adjustment for the acoustic field can be activated too. With the microphone (UC52),), which has a frequency response optimized for the “Free Field”, no correction is applied when the correction is set on “Free Field” (FF). When you set the correction on “Random Incidence” (RI), the correction for random incidence sound will be activated. This setting is necessary to perform measurements according to ANSI standards (see the parameter of the menu: CALIBRATION >> Microphone Response).

The HD2010UC/A sound level meter is suitable for measurements on site in a temperature range between –10°C to +50°C, in a static pressure range between 65kPa and 108kPa and in a relative humidity range between 25% and 90%. The microphone itself has defined drift coefficients of acoustic sensitivity with temperature and static pressure that imply a measurable drift of the Microphone-preamplifier-instrument chain, even though within the limits specified by IEC 61672:2002 new standard. The following table gives the maximum values of the acoustic sensitivity drift coefficients or the measurement error within the a.m. operating range, for the different microphones supplied with the HD2010 sound level meter.

HD2010UC/A - 51 - V4.1

PERIODIC CALIBRATION

The periodic calibration of the HD2010UC/A sound level meter is needed to ensure the traceability to the laboratory standards and is carried out in accredited laboratories. The HD2010UC/A sound level meter is calibrated at Delta Ohm Acoustic Laboratory before being supplied to the user.

“Factory” calibration, which is always made on new instruments and at every periodic calibration (every 2 years, at least), includes the measurements of the acoustic response in pressure of the microphone-preamplifier-instrument chain, stored on the sound level meter non-volatile memory, together with the microphone acoustic sensitivity. Right after the measurement of the acoustic response in pressure, also the Capacity Transducer Calibration (sound level meter electrical calibration including the microphone) is carried out, to be used as a reference for the calibrations made by the user.

Every time a periodic calibration of the sound level meter is carried out at the factory, calibration constants are stored as a reference for following comparisons. The factory calibration can be loaded onto the instrument to make a comparison or to correct a wrong calibration. This procedure will also load the instrument default parameters so that, is there are any data stored on memory, these will be deleted.

Follow this procedure to proceed with this operation:

 Download any data stored on memory  Ensure that logging is on STOP mode  Remove the external power supply, if connected  Remove one of the batteries: the instrument will obviously switch off (this operation assures

that all the sound level meter internal circuits are discharged)

 Wait some minutes: this operation ensures that all internal electronic circuits are discharged  Insert missing battery while holding down the ENTER key  The instrument will automatically turn on and will show a warning message indicating that fac-

tory parameters have been loaded

 Press CONTINUE to confirm and make an acoustic calibration to store calibration constants. If

this operation is not carried out, or in case the acoustic calibration should give a negative result, upon the next power on, factory calibration data will be replaced by those stored in the last successful calibration.

Electrical signals supplied by a generator connected to the HD2010UC/A preamplifier via a capacitive adapter (replacing the microphone) can be used for periodic tests. Specific capacitive adapter for supplied microphone is an accessory available from Delta Ohm. It’s possible to use other supplier’s capacitive adapters provided that the equivalent capacity of the device is within 15 pF and 33 pF.

Before carrying out electrical and acoustic laboratory tests, it’s necessary to disable spectral corrections on the equipment under test. The setting is the following:

• Menu >> Calibration >> Microphone Response Correction >> FF

• Menu >> Calibration >> Shield >> OFF

The frequency response check is made on a closed coupler under pressure field conditions, as for example using a multi-frequency calibrator B&K 4226. For more information on corrections to be applied to the frequency response please see the manual of UC52 microphone.

HD2010UC/A - 52 - V4.1

ELECTRIC CALIBRATION

The electric calibration, using the partition of charge injected into the microphone preamplifier in “charge amplifier” configuration (Capacitive Transducer Calibration), even if it cannot completely replace the acoustic calibration, provides however a useful means to keep under control the instrument drifts, microphone included. The figure on the right shows the diagram of the CTC technique consisting in sending an electrical signal to the preamplifier through a high stability capacitor, so that the output signal does not depend only on amplification, but also on the microphone capacity. Many of the microphone malfunctions reflect in a capacity drift identifiable by means of this calibration technique.

The electric calibration uses as a reference the result of the last acoustic calibration, and according to it corrects any possible drift of the instrument.

The electric calibration adjusts the acoustic response of the microphone-sound level meter chain, both for wideband channels, and for those with a constant percentage bandwidth. In case of high instrument drift with respect to the previous calibration, it is suggested to carry out an acoustic calibration and to check the instrument frequency response to verify that there are no other problems in the measuring chain.

Operating Procedure

Switch on the sound level meter, if it is the case, press STOP to finish the measurement in progress and make the following procedure:

1. Press PROG and use the DOWN arrow to select "Electric Calibration".

2. Press SELECT to start the function.

3. The inner signal generator will be turned on and the measured output signal will be com-

pared with the one detected in the last acoustic calibration. The value that appears on the display (51.3dBC in the example below), before starting calibration, is the valued measured by the microphone upon pressure of the PROG key, and is not relate to the calibration in progress.

ELECTRIC CALIBRATION Last:2003/01/01 10.00 Calibr. level 94.0dB

Leq dBC

51.3

YES

Run calibration

4. Press YES to continue and NO to quit.

Calibration

Signal Source

Transducer

CTC

-A

Charge amplifier

Cm + Cb+ C

= -

HD2010UC/A - 53 - V4.1

5. If you press YES, the calibration is run: wait till the procedure will be over.

6. At the end, the calibration result will be shown and you will be asked to confirm a new cali-

bration:

ELECTRIC CALIBRATION

Last:2003/01/01 10.00

Leq dBC

Confirm calibration

-0.1

Calibr. level 94.0dB

YES

7. Press YES (keypad LEFT key) to confirm or NO (keypad RIGHT key) to refuse the calibra-

tion just finished. At the end, the instrument will switch to the SLM display, in STOP mode.

The stabilization on a value far from the reference one, indicated by a ΔLeq higher than some tenths, means that one of the components of the microphone-preamplifier-instrument chain was affected by a considerable drift and if this difference exceeds the maximum limit admissible by the instrument, calibration will fail. In this case, refer to “Troubleshooting” (page 112), and if necessary contact our service department.

HD2010UC/A - 54 - V4.1

ACOUSTIC CALIBRATION

In order to keep the acoustic sensitivity of the microphone-sound level meter chain steady over time and in the different usage conditions, a reference sound source is used, which generates a pure tone at a reference frequency with a given pressure level, stable over time. For this purpose type 1 and type 2 (according to IEC 60942) acoustic calibrators compatible with UC52 microphone capsule are used. For the HD2010UC/A sound level meter are available Class 1 HD2020 and Class 2 HD2022 calibrators. The control that the reference sound level provided by the acoustic calibrator is correctly measured by the sound level meter (it is normally acceptable that the difference between the sound level measured by the sound level meter and the nominal level of the calibrator be lower than

0.5dB) has to be carried out before and after a series of measurements, to ensure that measured values are correct. When the difference between the calibrator sound level measured by the sound level meter and the nominal value is higher than 0,5dB , a new acoustic calibration has to be carried out.

Warning: to prevent damaging the sound level meter, it is important, during the calibration procedure, to follow carefully the on-screen instructions and the indications provided by this manual.

Operating Procedure

Switch on the sound level meter, if necessary, press STOP to finish the measurement on progress, and perform the following procedure. The program will automatically control that the warm-up time, indicated by a flashing W, is over.

1. Press PROG and, with the help of the DOWN arrow, select "Acoustic calibration". Press

SELECT to start calibration.

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ACOUSTIC CALIBRATION

Last:2003/01/01 10.00

Calibr.level 94.0dB

Leq dBC

Insert and turn on

the calibrator.

95.3

SELECT PROGRAM

Electric Calibration Acoustic Calibration Frequency Response ...

NEXT EXIT

2. The first screen shows the date of the last calibration (Date:…) and, in the line below, the

calibrator sound level to be used in the calibration in progress (this value can be modified,

before starting the calibration program, by selecting “Calibration Level” from the MENU:

see page.44). Gently insert the microphone in the calibrator hole and switch it on.

3. Select the sound level indicated on the sound level meter display (94dB is the reference

value), then press NEXT to continue.

4. Now, the instrument measures the sound level applied and waits for it to become steady: the

measured level will be displayed. The indication "Waiting for level stabilization…" will be

viewed.

When the sound level has stabilized, the measured value is compared to the reference one

and if the difference is acceptable, it is logged. In this case, the message “Turn off the

Calibrator” will appear. Press NEXT to continue.

HD2010UC/A - 55 - V4.1

ACOUSTIC CALIBRATION Last:2003/01/01 10.00 Calibr.level 94.0dB

Leq dBC Turn off the calibra-

tor.

94.0

5. After the acoustic calibration, the electric calibration will be automatically started. This

stage of the procedure generates the reference data for the following electrical calibrations.

ACOUSTIC CALIBRATION

Last:2003/01/01 10.00

Calibr.level 94.0dB

Leq dBC

Confirm calibration?

-0.1

ACOUSTIC CALIBRATION Last:2003/01/01 10.00 Calibr.level 94.0dB

Waiting for electric calibration ...

Leq dBC

12.5

YES

6. At the end, if the values of the electrical calibration are acceptable, press YES to confirm the

new calibration (LEFT arrow of the keypad); press NO if you want to cancel the whole cali-

bration (RIGHT arrow of the keypad).

7. Finally, the microphone polarization check is carried out. Wait until "Take out the calibra-

tor" appears (take out the preamplifier from the calibrator".

ACOUSTIC CALIBRATION Last:2003/01/01 10.00 Calibr.level 94.0dB

Take off the calibrator

ACOUSTIC CALIBRATION Last:2003/01/01 10.00 Calibr.level 94.0dB

...

Leq dBC

Checking microphone polarization

-0.1

EXIT

Leq dBC

96.1

8. Take out the preamplifier from the calibrator and press EXIT.

HD2010UC/A - 56 - V4.1

9. The procedure is over.

If calibration constants were incompatible with a correct working of the instrument, calibration would fail and the message “Calibration failed! Consult the manual” would appear. In this case, refer to “Troubleshooting” (page 112) and if necessary contact our service department.

HD2010UC/A - 57 - V4.1

MICROPHONE REPLACEMENT

The HD2110 sound level meter is calibrated in the factory in conjunction with the microphone. If the microphone capsule sensitivity deviates too much from factory calibration, the sound level meter blocks acoustic calibrations and reports the microphone as damaged.

The acoustic calibration can therefore fail even if the capsule is replaced or repaired, or if us-

ing a capsule with different characteristics from the one supplied.

If you wish to change the microphone capsule, you must use the relevant wizard in Noise Studio under the menu “Instrument management >> New microphone”. The procedure, which requires a certified sound calibrator to be used, is described in detail in Noise Studio’s online Help.

DIAGNOSTIC CHECK

The diagnostic test is a program that verifies a series of electrical critical parameters. The following are checked: supply voltages, microphone polarization and sensitivity, the type of preamplifier and the temperature. At the end of the procedure, should it fail, a table will be shown with the results of the inspection. If necessary, refer to “Troubleshooting” page 112), and if necessary contact our service department.

HD2010UC/A - 58 - V4.1

REVERBERATION TIME MEASUREMENT

The “Reverberation Time” program is available as an option on the HD2010UC/A sound level meter. The measurement of reverberation time requires the use of a sound source, an omnidirectional microphone and a measuring device that can measure the sound decay in the environment being tested. The reference standards for reverberation time measurements are the EN ISO 3382/2008 and the EN ISO 354/1985. Typical applications of this function are the measurement of acoustic parameters in theatres, auditoriums, rooms for music reproduction and also the determination of airborne sound insulation of buildings like apartments, schools etc.

INSTRUMENTATION AND MEASUREMENT CONDITIONS

The EN ISO 3382-2 Standard: “Acoustics -- Measurement of room acoustic parameters -- Part 2:

Reverberation time in ordinary rooms” was updated in 2008. This standard sets the criteria and imposes the choices on which instrumentation to use and on measurement conditions in order to make the results as repeatable and comparable as possible. Concerning the sound source, it has to meet the precise requirements for omni-directionality of emission and signal/noise ratio in all concerned acoustic bands, typically in the octaves from 125Hz to 4kHz (or third octave from 100Hz to 5KHz). The omni-directionality must be accurately verified: the maximum acceptable deviations, as an average for each 30° around the source, are the following:

Frequency [Hz] 125 250 500 1000 2000 4000

Max Departure [dB] ±1 ±1 ±1 ±3 ±5 ±6

In order to evaluate the minimum acoustic level of the source for each octave band so as to measure the reverberation time, analysis of a decay equal to at least 20 dB, starting from 5 dB under the stationary level, is sufficient. By estimating that the background noise of the environment, in order to be negligible, should be at least 10dB under the minimum level considered for the decay not to influence it significantly, the emitted sound source level should be at least 30 dB higher per each band compared to the background noise. Normal speakers are usually suitable to be used as sources for reverberation time measurement because of the typical strong directionality of sound emission. Usually a special sound source composed of a series of twelve loudspeakers arranged on the figure of a dodecahedron is used.

For the measurement technique which uses an impulse source, gun shots or balloon explosions are normally used. Concerning the microphone choice, it is important to evaluate its directionality and its fre-

quency response characteristics. In fact, ½” microphones with frequency response optimized for pressure acoustic field are the best choice. Alternatively it is possible to use microphones optimized

for random acoustic field or for free field applying in such case the correction for random noise incidence.

Measurement position

The measurement position is important because the measurement results depend on the position both of the source and of the microphone. It is therefore fundamental to consider a number of positions suitable to describe the environment being tested, both for the source and for the microphone. The position of the source should consider the actual points where the sound source will be located according to the most usual occupancy of the environment. Typically, a minimum number of two or three source positions are considered, except for the case of a small conference room where it is possible to consider only the single typical position of the lecturer. The height from the floor is usually equal to 1.5m.

HD2010UC/A - 59 - V4.1

For each position of the source, different microphone positions need to be analyzed by considering the actual distribution of the listeners. The distance of the measurement points should be at least 2m and they must be at least 1m from walls or reflecting surfaces. The average height from the floor (considering that listeners are usually seated) should be 1.2m. The minimum distance from the source must be equal to:

d 2

min

≈

where

V is the volume of the environment in m

, c is the sound speed (343 m/s at normal tempera-

ture) and

T is the estimated value for the reverberation time. Usually the minimum distance is not

less than 3 meters.

The analyzing device can be reduced to the minimum by using a simple recorder that can guarantee the minimum time resolution required to measure the decay. ISO 3382 considers two possible types of measurement for the sound level to be registered: the sampling of the acoustic level exponentially weighted and the recording of linearly integrated levels. In case the acoustic level exponentially weighted is measured, it is necessary for the exponential average time to be lower than and as close as possible to T/30 where T is the reverberation time.

For the linear integration sequence, the time of each integral must be lower than T/12. There are no advantages in reducing the linear integration time below this value. The HD2010UC/A carries out a linear integration of sound level on time intervals corresponding to 1/32s; according to ISO 3382, it can therefore perform reverberation time calculations starting from a reverberation time of 0.375s.

The measurement device must estimate the reverberation time by measuring the gradient of the decay curve over a decay of at least 20 dB and then estimating the necessary time for a decay equal to 60 dB, according to the definition of reverberation time. Of course, with this type of device the recording and the measurement needs to be repeated for all the positions of the source and the microphone and for all the octave and third octave bands.

Using a modern frequency analyser as the HD2010UC/A it’s possible to carry on the analysis in parallel on all the frequency bands; this analysis is known as multi-spectrum analysis, as spectra are calculated at regular time intervals.

Estimations of the reverberation time T10, T20 and T30

The reverberation time measurement taken by analyzing a reverberation sample equal to 60 dB is usually not feasible due to the insufficient signal/noise ratio of the source. The reverberation time is usually estimated starting from the measurement of the decay time over a limited stretch equal to 20dB or 30 dB, starting from 5 dB under the stationary level. These estimates of the reverberation time are indicated as T

(20) (or T20) and T60(30) (or T30).

In practice a linear interpolation is carried out using the Ordinary Least Squares on the decay starting from the point 5 dB lower than the stationary level and stopping, for example, 35 dB below this level. The gradient of the straight line gives the decay rate in dB/s from which the reverberation time can be extrapolated.

HD2010UC/A - 60 - V4.1

MEASUREMENT USING A STATIONARY NOISE

To perform the reverberation time measurement with the sound source interruption technique, an omnidirectional sound source (typically a dodecahedron loudspeaker) should be used, powered by a wide band signal that covers the acoustic spectrum required for the measurement.

The wide band signal issued by the source is usually of two types:

white or pink. The issued

noise is defined as “

white” when the spectrum density is constant all over the audio frequency

range. It is defined as “

pink” when the spectrum density is inversely proportional to the frequency.

Analyzing the spectrum of a white noise source by bands with a constant percentage width, as octave or third of octave bands, the sound level increases with frequency by 3dB per octave. Instead, in the case of the pink noise source, the sound level spectrum, analyzed by constant percentage bands, remains constant over the whole frequency range. The analysis can be done sequentially for each band or in parallel for all the bands. For the sequential analysis it is possible to use a source which has already been filtered so as to issue energy only in the band concerned, with a perceptible improvement of the signal/noise ratio. In the case of the parallel analysis, by therefore simultaneously acquiring the decay of all measurement bands, the source will usually be a pink noise source that can overcome by at least 30 dB the background noise for all the concerned bands, at least from 100 Hz to 5 kHz. To perform the measurement, firstly a stationary regular sound needs to be generated by maintaining the source on at a constant volume for a time of at least one fifth of the reverberation time.

In addition to the sampling of the constant level reached in the environment and of a decay of at least 20dB, the background noise needs to be sampled in order to assess the measurement conditions.

Because of the random nature of the excitation signal, the measurement technique with the sound source interruption presents a remarkable variability in the measurement, especially at low frequencies and therefore requires the calculation of averages in order to reduce the irregularities of the decay curve and to improve the accuracy of the slope measurement. The minimum number of measurements according to the standard is equal to 3. According to ISO 5725, the repeatability of the reverberation time measurement according to the number of averages calculated is equal to:

370

;

200

BNT

r ==

respectively for

and T20 where r is expressed as a percentage and B is the bandwidth of the filter

used, respectively equal to 0.71f

and 0.23fc for filters with bandwidth equal to an octave or third of

octave. In addition to calculating the reverberation time T

or T20 it is necessary to analyze the de-

cay curve visually to check the possible presence of anomalies in the decay and also for possible double gradients

. It needs to be remembered that if the linear correlation coefficient calculated with the Ordinary Least Square method on the interpolated stretch is lower than 0.95 it is not possible (according to ISO 3382) to consider the measurement valid and therefore the reverberation time cannot be defined. In some cases it is possible to measure two different slopes, one for the initial stretch of the decay curve and one for the final stretch.

According to ISO 3382 the signal/noise ratio must respectively be at least 45 dB and 35 dB for the T

and T20 measurements.

HD2010UC/A - 61 - V4.1

MEASUREMENT USING AN IMPULSIVE NOISE

ISO 3382 standard contemplates the possibility of calculating the reverberation time from the impulse response of the environment being tested by using a numeric technique developed by Schroeder. This technique allows, starting from the measurement of the environment response to the sound impulse, to obtain the same decay curve that would have been measured by the stationary noise technique. Indeed, each decay curve obtained using this technique corresponds to the average of an infinite number of sound decays obtained using the stationary noise technique, as demonstrated by Schroeder and as recognized by ISO 3382 that considers the repeatability of a single measurement with the impulse response technique equal to the repeatability associated to the average of 10 measurements carried out using the stationary noise technique. The impulse response can be obtained by using different methods, and not necessarily using a sound source of an impulsive nature. Let us only consider the example of the impulsive source generated by a gun shot or the explosion of a balloon, as they are the most frequently used, even though they are not always usable or advantageous.

From the idea that the impulsive source produces an ideal impulse, the signal detected will be the direct response to the impulse of the environment. This approach is radically different to that of the stationary noise source, as no stationary conditions are reached and therefore the answer is strongly dependent both on the position of the source and of the microphone. The reverberation times measured directly from the decay of the impulse response are slightly lower than those produced by the decay of a stationary noise and do not coincide with the Sabine’s definition.

Schroeder’s Integral

Schroeder (1965) demonstrated that the decay defined by Sabine can be obtained from the impulse response calculating the integral of the response itself. Such an integral must be calculated on the square of the impulse response, moving backward from the end of the decay up to the instant when the impulse was received. Particular attention must be given to the choice of the start time for the integration. Indeed, by choosing too long a time, that is to say, longer than the decay interval of the sound level, an integrated decay curve will be obtained that will show an imaginary double gradient caused by the integration of the background noise. In contrast, by choosing a time too close to the beginning, that is to say, near to the instant when the impulse was received, the measurement dynamic will be reduced, which is useless. The ideal choice is the right compromise between maximizing the decay length and minimizing the effect of the background noise. Consequently, the measurement of the background noise is extremely important when using the impulsive source technique, and must be measured with the maximum care in order to avoid completely distorting the measurement of the reverberation time. Delta Ohm’s sound level meter HD2010UC/A can automatically perform the backward integration of Schroeder by applying advanced numeric techniques to remove the undesirable effects of the background noise. In the case where two different gradients of the integrated decay curve can be identified, the two relevant estimated reverberation t imes can be reported from the slope of the respective decay segments, which must be at least 10 dB each.

Early Decay Time EDT

In addition to the traditional reverberation time, starting form the integrated impulse response, the

Early Decay Time EDT can be obtained from the first 10dB of the decay itself. Com-

pared to the traditional reverberation time T correlated to the physical properties of the measured environment, the EDT is correlated with the subjective perception of the reverberation, and is therefore useful to evaluate the dependence of the EDT/T ratio on frequency in the different points of the environment.

HD2010UC/A - 62 - V4.1

OPERATING PROCEDURE FOR REVERBERATION TIME MEASUREMENT

In this chapter we will describe the steps needed to measure the reverberation time. Turn on the sound level meter and enter the program selection mode by pressing

PROG:

56.9

60.8

79.3

110

01:08:25

Tint= s

LFp

Leq

Lpk

dBA

dBC

2004/01/01 10 00 00

Batt 95% Mem 92.5%

SELECT PROGRAM

Memory Navigator Electric Calibration Acoustic Calibration ... Reverberation Time

By using the arrows select the program "Reverberation Time" and confirm with

SELECT

2004/01/01 10 00 00

Batt 95% Mem 92.5%

SELECT PROGRAM

Memory Navigator Electric Calibration Acoustic Calibration ... Reverberation Time

The program must be loaded into the memory: to continue, press the left arrow of the display keyboard (

YES) and, on the next page, press the right arrow corresponding to CONTINUE.

WARNING !

Please confirm

loading of

REVERBERATION TIME

program

Automatic power off

Change effective

after power on

WARNING !

YES NO

The sound level meter will automatically turn off.

If the option to measure the reverberation time is not present, a warning message will appear: "Program not enabled.

Please contact the manufacturer". In this case you need to contact your vendor to purchase this feature.

HD2010UC/A - 63 - V4.1

Turn it back on with the ON/OFF key: a written confirmation of the activation of the reverberation time measurement program will appear.

activated.

WARNING !

REVERBERATION TIME program

The page that now appears is the basic page:

From top to bottom are shown: the maximum level in octave bands reached by the noise source (LO max), the background noise level in octave bands (LO res), the Early Decay Time EDT and the three estimations of the reverberation time T

, T20 and T

each with the correlation coeffi-

cient “r”.

Before starting the reverberation time measurement it is convenient to verify the source sound level and perform any preliminary investigation in order to set the noise generator to measure the reverberation time. The Profile view shows 8 times per second the maximum equivalent level integrated every 1/32s. The parameter can be selected for the octave and third of octave bands (

op-

tional on 2010UC/A). In the views concerning the frequency spectrum, two spectra per second are

displayed as maximum band levels linearly integrated every 1/32s. The page of the six numeric parameters is not active until the reverberation time has been measured. When the source level has been verified and the signal/noise ratio is sufficient, the reverberation time measurement can be started. The sound level meter guides the user through the whole measurement procedure by means of messages on the display.

The sound level meter and the noise source must be set up (impulsive or continuous according to the type of measurement selected) and, when ready, continue by pressing the

PROG key.

HD2010UC/A - 64 - V4.1

Measurement of the background noise

The first step involves the measurement of the background noise without any other noise sources: when ready press the GO key.

The current noise level is recorded and integrated for two seconds and then saved in the sound level meter internal memory.

In the next step (04) the type of noise source that will be used for the measurement is chosen: continuous noise source (NOISE) or impulsive source (IMPULSE). According to your choice, the measurement session will proceed in two different ways: first, the sound source interruption technique will be illustrated, and then the integrated impulse response.

Select sound source:

REVERBERATION TIME

Batt:100% Mem: 95%

Step 04

HD2010UC/A - 65 - V4.1

Sound source interruption

If you use the continuous sound source interruption, press the central NOISE key.

Turn on the source.

REVERBERATION TIME

Batt:100% Mem: 95%

Step 0

Activate the sound source and press the NEXT key.

Confirm level

stabilization.

REVERBERATION TIME

Batt:100% Mem: 95%

Step 06

Wait until, according to the environment dimensions, the sound of the source stabilizes. Usually 4-5 seconds are enough even for wider environments, then proceed pressing the NEXT key.

Turn off the source

within 5 seconds.

REVERBERATION TIME

Batt:100% Mem: 95%

Step 0

HD2010UC/A - 66 - V4.1

Now turn the sound source off within 5 seconds: the sound level meter will automatically measure the environment noise decay and will perform the calculations. For the entire duration of the measurement (6 seconds from the source being turned off) avoid undesired noises that could affect the measurement. The following page will appear at the end:

Reverberation

calculated.

REVERBERATION TIME

Batt:100% Mem: 95%

Step 20

Time

Press VIEW to display the results of the measurement.

Using the sound source interruption method, the EDT value is not calculated in the measurement of the reverberation time.

The sound level meter gives a complete description of the measurement both in the form of a table and graphically. See the paragraph describing the results: "Reverberation Time - Analysis of the Results".

HD2010UC/A - 67 - V4.1

Integrated Impulse Response

Using the integrated impulse response method, when at step 4, select IMPULSE…

Activate the source

within 5 seconds.

REVERBERATION TIME

Batt:100% Mem: 95%

Step 0

Select sound source:

REVERBERATION TIME

Batt:100% Mem: 95%

Step 04

… and, as indicated in the next page, activate the impulsive noise sound source (gun shot, balloon explosion,…)

within 5 seconds from pressing the button.

The sound level meter will automatically measure the environment noise decay and will perform the calculations. For the entire duration of the measurement (6 seconds from the source being turned off) avoid undesired noises that could affect the measurement. The following page will appear at the end:

Press the

PROG key to access the next step where you can save (SAVE key), review the val-

ues again (VIEW key) or close the current measurement session to start a new one (EXIT key).

HD2010UC/A - 68 - V4.1

REVERBERATION TIME

Batt:100% Mem: 95%

Step

Reverberation Time

calculated.

To restore the standard SLM mode of the sound level meter and to exit the reverberation time measurement program, turn off the instrument (ON/OFF button) and then turn it back on.

Measured not correctly performed

The measurement procedure is terminated if the maximum delay of 5 seconds is not satisfied for the generation of the impulsive noise or the continuous source turn off; the following message appears:

REVERBERATION TIME

Batt:100% Mem: 95%

Step

Reverberation Time

not measured.

The same message is displayed if the signal/noise ratio between the generated signal and the background noise is not large enough. Besides, one or more results may be missing if the signal/noise ratio between the generated signal and the background noise is not sufficient to perform the respective reverberation time estimations, as shown in the following page.

HD2010UC/A - 69 - V4.1

Reverberation time – Analysis of the results

At the end of the measurement, as indicated above, the results are supplied in a table or graphically.

Parameters

Pressing the right arrow on the display keyboard corresponding to the VIEW key brings the table up onto the screen.

From top to bottom are shown the maximum octave band level reached by the noise source (LO max), the octave band background noise level (LO res), the first decay time EDT and the three estimations of the reverberation time T

, T20 and T

each with the correlation coefficient “r”. The results of the measurement refer to the variable indicated in the first two lines of the table (LOmax and LOres in the picture above). To display another variable press the SELECT button: the current variable starts blinking. Using the arrows select the new variable from those available:

•

LO: sound pressure level in octave bands from 125Hz to 8KHz

•

LTO: sound pressure level in third octave bands from 100Hz to 10KHz (if third octave op-

tion is installed).

Pressing the right arrow it’s possible to select the central frequency of the filter allowing to modify their value. Pressing the left arrow returns to the selection of the parameter to be displayed.

HD2010UC/A - 70 - V4.1

Confirm the selection by pressing the ENTER key. The sound level meter will calculate the new values and update the page showing the results.

To move from the table of the results to the graphs (profile, octaves and thirds of octave) repeatedly press the

MODE button: as indicated below, by pressing this key the display will move to the time

profile view, to the octave spectrum, to the third of octave (optional on

HD2010UC/A) one and

then return to the results.

Profile

The Profile view shows the time trend of the acquired sound level. If you used the impulsive source method the graph shows Schroeder’s integral of the sound level acquired. The following picture shows an example of a time profile obtained using the impulsive source method.

The upper number on the right (3.09) indicates the time in seconds in correspondence of the right border of the visible window of the graph. When the cursors are

not active, you can move the

graph horizontally on the time axis using the arrows. This function helps examine the decay profile when the measurement is taken in wide spaces where the reverberation time is longer than three seconds. The integration time (fixed at 1/32s) and the central frequency of the constant percentage bandwidth filter are shown below.

HD2010UC/A - 71 - V4.1

The parameter displayed (LOeq at 125Hz in the picture’s example) is the same parameter which the parameters view refers to. Even here it is possible to select, using the SELECT button and the arrows, the parameter to be displayed. Upon confirmation with ENTER, the profile graph and the values displayed in the parameters view are updated.

The profile can be analyzed by using the

cursors. By repeatedly pressing the CURSOR but-

ton the cursors

L1 and L2 are sequentially activated, and finally the two cursors ΔL. The cursor se-

lected blinks and the relevant data appear on the display in the second line from the top. When they are active individually (L1 or L2), the display shows the noise level and the corresponding time in seconds. When they are both active in "tracking", the second line of the display shows in this order: the difference Δ

L=L2-L1 of the noise levels, the time interval between L1 and L2 and the rever-

beration time estimation calculated by interpolating the part of the decay between L1 and L2.

Reverberation time by octave and third of octave

By pressing the MODE key once, the display shows the estimation of reverberation time by

octaves soon after the results view. Pressing the

MODE button again you can see the estimation by

the third of octave bands (optional on HD2010UC/A). The spectrum by octave bands shows the reverberation times T

, T20, T30 and the early decay time EDT for each band from 125 Hz to 8 kHz, and the spectrum by third of octaves from 100 Hz to 10 kHz. The times are expressed in seconds.

T10

0.1

s 1

The variable (T10, T20, T30 or EDT) are selected as usual by

SELECT and the arrows: upon con-

firmation by pressing

ENTER, the page is refreshed to show the new results.

The

CURSOR button activates the cursors: the following data are reported when the compo-

nent is selected on the graph by the blinking cursor (RT@100 Hz in the following example): the reverberation time estimation and the respective correlation coefficient.

HD2010UC/A - 72 - V4.1

T10

RT@100 1.34 1.00

0.1

s 1

Display and printing of the results

The set of results obtained with the analysis of the reverberation time can be sent to a PC, connected via the special serial cable supplied with the device. The HyperTerminal program, supplied with all versions of Windows, can be used to receive the data. The chapter "” explains how to connect to a PC, the download of the data and their storage into a file.

In addition to the values acquired as a table, all the main characteristics of the sound level meter and measurement conditions are supplied.

An deeper analysis of the results can be performed by using the

Noise Studio program sup-

plied free of charge with the sound level meter. This software displays, processes, prints and exports the data stored in the sound level meter using the SAVE command (

PROG >> SAVE) both as tables

and as 2D and 3D graphs. The post-processing module (available as an option) NS3 of Noise Studio package allows to download, display and analyse the reverberation time measurements stored in the sound level meter memory. Specific functions to analyse and correct the reverberation time decay curves and to calculate absorption, airborne sound insulation and impact noise are implemented in NS3 software module. Please see program’s online Help menu for the details.

Important: with the saving operation (SAVE key), the current measurement session is closed and

the sound level meter is set up for a possible new session. By using the Navigator feature (

PROG

>> Navigator), it is possible to review the measurement sessions saved, directly on the sound level meter display, but with some limitations: compared to the open session, the parameter results and time profile views

cannot be displayed.

To display the different estimations (EDT, T

, T20 and T30) of the reverberation time for the octave

and third of octave bands

optional on HD2010UC/A) just press the MODE key repeatedly.

Direct printing of results, pressing the

PRINT button, is active for the saved sessions too.

HD2010UC/A - 73 - V4.1

FIRMWARE UPDATE

The firmware, that is the program managing all of the instrument functions, can be upgraded by transferring the file from a PC to the HD2110C/A through the serial/USB port. In this way, all the instrument functions can be upgraded.

To make the upgrade, you need to use Noise Studio “firmware upgrade” function. See “Noise Studio Handbook” online help for details.

OPTIONS UPGRADE

Instrument options (HD2010.O1 “Third Octaves” and HD2010.O4 “Reverberation Time”) can be bought and installed also after sound level meter initial purchase; they can be directly activated by the user using the Noise Studio software. Alternatively it’s possible to send the instrument to Delta Ohm for upgrade.

To activate the specific option can be used the “Option Upgrade” function in Noise Studio along with the activation code supplied after option purchase. Please see the online Noise Studio Handbook for details.

Note: option

HD2010.O1 “Third Octave” requires the laboratory Calibration of filters and can

normally installed at Delta Ohm technical department.

HD2010UC/A - 74 - V4.1

BATTERY SYMBOL AND BATTERY REPLACEMENT

The battery symbol in the upper right corner of the display constantly provides the charge status of the instrument batteries. The more the batteries discharge, the more the symbol gets “empty”…

... when the battery voltage reaches the minimum value for a correct operation, the symbol flashes. At this point, only 5 minutes of autonomy are left and batteries should be replaced as soon as possible.

If the instrument is still used, the battery voltage will decrease still further and the instrument cannot ensure anymore a correct measurement; data recording is automatically interrupted, as well as data logging and the instrument goes into STOP mode. Under a given level, the instrument will automatically shut off. Data stored on memory will remain. The instrument cannot be switched on again until the battery level remains low.

The battery charge level is available on the menu main screen and on the program screen, expressed as a percentage value. Press MENU or PROG to view it. When the level is indicated by 0%, 5 minutes of autonomy are left. The battery symbol changes into a plug when the instrument is connected to an external power supply.

Note: the battery symbol also flashes when the auto power-off is disabled (AutoPowerOFF = OFF).

To replace the battery, switch the instrument off, and then unscrew anticlockwise the two screws of the cover of the battery space. After replacing batteries (4 1.5V alkaline batteries - type AA), close again the cover and fasten the two screws clockwise. Check date and time. If this operation takes less than two minutes, no clock adjustment should be needed.

As an alternative to alkaline batteries, you can use rechargeable batteries. Batteries with lower capacity usually show greater impedance, causing a worsening of the electrical noise generated by the sound level meter, with repercussions on the measurement dynamic. Therefore zinc-carbon and rechargeable NiCd batteries are not recommended.

HD2010UC/A - 75 - V4.1

WARNING ABOUT THE USE OF BATTERIES

• Batteries should be removed when the instrument is not used for an extended time.

•

Flat batteries must be replaced immediately.

•

Avoid loss of liquid from batteries.

•

Use waterproof and good-quality batteries, if possible alkaline.

•

If the instrument does not turn on after battery replacement:

 Remove one of the batteries  Wait at least 5 minutes for the sound level meter internal circuits to discharge  Put the new battery in. If the batteries are charged the instrument should turn on

automatically.

INSTRUMENT STORAGE

Instrument storage conditions:

•

Temperature: -25...+70°C.

•

Humidity: less than 90% R.H. no condensation.

•

To be avoided:

High humidity storage.

Direct sun irradiation over the instrument.

High temperature source near the instrument.

Presence of strong vibrations.

Steam, salt and/or corrosive environments.

The instrument case is in ABS plastics material and the protection belt in rubber: do not use any solvent for cleaning.

HD2010UC/A - 76 - V4.1

SERIAL INTERFACE

The instrument is provided with a versatile serial interface with double protocol: RS232C and USB. The interface settings depend on the item “MENU >> Instrument >> Input/Output >> Serial Disp.”:

•

PRINTER: connection with RS232 interface of the portable serial printer.

•

MODEM: connection with RS232 interface to a modem.

•

RS232: connection with RS232 interface to a PC equipped with COM type physical port.

•

USB: connection with USB interface to a PC where the VCOM driver is installed.

The RS232 setting allows to connect the sound level meter to a COM type physical port of a PC. This connection does not need any particular program to work as it is allowed by the common architecture of PC equipped with RS232 (COM) port. The maximum speed of data transfer is up to 115200 baud.

In the last few years, in order to meet the needs of the new audio and video peripherals, the USB standard has been used for information serial transfer. Recently many PC manufacturers do not offer the COM type ports any longer, which are usually replaced by the USB type ports. There is a 4 wire connection, two wires for information transfer, other two wires for the power supply. As far as the data transfer is concerned, the main differences with respect to the RS232 interface RS232 are:

•

The transfer occurs in simplex mode, i.e. it’s impossible to carry out simultaneously a

transfer in both the directions

•

The data are transferred as package size

•

The transfer time is defined by only one of the two units (the master)

•

The transfer speed is fix at 1.5Mbit/s, 12Mbit/s or 480Mbit/s according to the USB stan-

dard and the kind of connected device.

The two devices connected through the USB interface are identified as master and slave. The master supplies power to the slave and decide the sense and the transfer time scheduling. The USB interface of sound level meter is a sort of slave and then it has to be connected to a USB master able to supply with the necessary power and to manage the communication.

The sound level meter HD2010UC/A is equipped with a serial connecting cable for PC with COM type ports (code

HD2110RS) or USB (code HD2110USB).

The

HD2110/RS cable is a null-modem cable with 9-way sub D female connector. The

HD2110USB cable is fitted with an USB connector type A. On request, the connection cable for modem or printer (DCE) with a 25-way sub D male connector (code

HD2110CSM) or with a 9-

way sub D male connector (code

HD2110CSP) can be supplied.

When the item “MENU >> Instrument >> Input/Output >> Serial Device” is set on “PRINTER”, “MODEM” or “RS232”, the following signals are connected to the 8 pin male connector type M12 available on the instrument:

Pin Direction Signal Description

1 Input CTS Clear to send 2 Output DTE DTE ready 3 Input DCE - CD DCE ready – Carrier detect 4 Output VDD Power supply 3.3V 5 Input RD Receiving data channel 6 Output RTS Request to send 7 Output TD Transmitting data channel 8 - GND Reference ground

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The following signals are connected to the 9 pin sub D male connector of the HD2110RS cable:

Pin Direction Signal Description

1 DCE >> HD2010UC/A DCE - CD DCE ready – Carrier detect 2 DCE >> HD2010UC/A RD Receiving data channel 3 HD2010UC/A >> DCE TD Transmitting data channel 4 HD2010UC/A >> DCE DTE DTE ready 5 - GND Reference ground 7 HD2010UC/A >> DCE RTS Request to send 8 DCE >> HD2010UC/A CTS Clear to send 9 HD2010UC/A >> DCE VDD Power supply 3.3V

When the item “MENU >> Instrument >> Input/Output >> Serial Device” is set on “USB”, the following signals are connected to the 8 pin male connector type M12 available on the instrument:

Pin Direction Signal Description

2 I/O DP Data + 4 I/O DM Data 6 Input VBUS Power supply 5V 8 - GND Reference ground

When the sound level meter is connected via RS232 to an active terminal (DCE active)

he auto power off is disabled and the instrument cannot be switched off. If the instrument is

off, the connection to an active terminal (DCE active) will turn it on. Standard parameters of the instrument serial transmission are:

•

Baud rate 38400 baud

•

Parity None

•

N. bit 8

•

Stop bit 1

•

Protocol Hardware.

Data transmission speed can be changed through the "Baud rate" parameter inside the menu (MENU >> Instrument >> Input/Output >> RS232 Baud Rate – see page 41). Available baud rates are: 230400, 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200, 600, 300. The other transmission parameters are fixed. The 2010UC/A is provided with a complete set of commands to be sent via the RS232 serial port of a PC.

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COMMUNICATION PROTOCOL

The command consists of ASCII strings with a variable length, ending in CR-LF. The instrument provides always a response, after a command has been received; if the command is not accepted, the response string is always NAK-CR-LF. It is possible to disable the response, when it is not expressly requested by the command, modifying the VERBOSE setup parameter (see the SET paragraph). Commands are divided into 5 groups, as shown in the following table.

Group N. of Commands Description

SET 65 SETUP: parameter configuration

KEY 21 KEY: keyboard simulation

STT 4 STATUS: instrument status

DMP 6 DUMP: memory dump

Each group contains a given number of commands. Each command is identified by a specific string. The generic syntax of a command is the following:

<group>:<command>:<value>:CR-LF

Ex.: “SET:INPUT_GAIN:10\r\n”

sets the INPUT_GAIN parameter to 10dB (see SET paragraph). Only capital characters are acknowledged. Each token can be shortened at the minimum number of characters that univocally identify it. The example can be shortened as follows:

“SET:INP:10\r\n”

Here are the possible command formats:

A3 - SET:INTEGRATION_TIME:<{SS,MM,HH}>:<value>CRLF A4 - SET:TIME:<hh>:<mm>CRLF A5 - SET:DATE:<yyyy>:<mm>:<dd>CRLF A6 - SET:x_SLM_PARAMETER:<Parameter abbreviation>:<parameter attribute>CRLF A7 - SET:PROFILE_PARAMETER:<Parameter abbreviation>:<parameter attribute>CRLF A8 - SET:<COMMAND>:<value>CRLF A10 - SET:<COMMAND>:?CRLF C1 - KEY:<COMMAND>CRLF C2 - KEY:<COMMAND>:<value>CRLF D1 - STT:<COMMAND>:<OPTION>CRLF E1 - DMP:<COMMAND>CRLF

If you enter “?” properly in the string, you can get either a help for the compilation of the desired command or the current status of the instrument configuration parameters. Here are the formats of the commands that use the “?” character.

0 ?CRLF Provides the list of the groups of commands A9 SET:?CRLF Provides the command list of the SET group A10 SET:<COMMAND>:?CRLF Provides the current status of the specified command C3 KEY:?CRLF Provides the command list of the KEY group D2 STT:?CRLF Provides the command list of the STT group D3 STT:<COMMAND>:?CRLF Provides the current status of the specified command E2 DMP:?CRLF Provides the command list of the DMP group

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SET Group (SETUP)

The following table shows the list of the commands of the SET group (SETUP)

Command Format Description

INSTR_MODEL A10

Instrument model - UNMODIFIABLE

INSTR_NUMBER A10

Instrument serial number - UNMODIFIABLE

INSTR_VERSION A10

Instrument version - UNMODIFIABLE

MIC_MODEL A10

Microphone model –UNMODIFIABLE

MIC_NUMBER A10

Microphone serial number –UNMODIFIABLE

MIC_TYPE A10

Type of microphone –UNMODIFIABLE

CLASS A10

Class of tolerance –NON MODIFICABILE

MEM_SIZE A10

Memory size –UNMODIFIABLE

OPTIONS A10

Firmware options –UNMODIFIABLE

EXT_RNG A10

Extended range –UNMODIFIABLE

TIME A4

Time (hh:mm)

DATE A5

Date (yyyy/mm/dd)

DISP_CONTRAST A8

Displa y contrast (3÷9, default: 5)

AUTO_POWEROFF A8

Instrument auto-power-off (ON/OFF, default: ON)

BAUD_RATE A8

Baud rate RS232

DEVICE A8

Serial device

INPUT_GAIN A8

Input gain

INTEGRATION_TIME A3

Integration time in s, m (1÷59) or h (1÷99)

REPORT_TIME A8

Report Time

ERASE_TIME A8

Erase interval

EXCHANGE_RATE A8

Exchange rate in dB (3÷5)

DOSE_THRESHOLD A8

Dose threshold in dB (0÷140)

CRITERION_LEVEL A8

Criterion level in dB (60÷140)

VERBOSE A8

Acknowledge (ON/OFF, default: ON). Always ON upon power on.

OVERLOAD_LEVEL A8

Overload level in dB (20÷200)

INT_MODE A8

Integration Mode

1_PERC_LEVEL A8

Percentile level 1 in % (1 ÷ 99, default: 1)

2_PERC_LEVEL A8

Percentile level 2 in % (1 ÷ 99, default: 10)

3_PERC_LEVEL A8

Percentile level 3 in % (1 ÷ 99, default: 50)

4_PERC_LEVEL A8

Percentile level 4 in % (1 ÷ 99, default: 90)

1_SLM_PARAMETER A6

SLM parameter 1 (see parameter list)

2_SLM_PARAMETER A6

SLM parameter 2 (see parameter list)

3_SLM_PARAMETER A6

SLM parameter 3 (see parameter list)

SPECT_AUX_POND A8

Spectrum auxiliary weighting

STAT_PARAMETER A6

Parameter for statistical analysis

EVN_TRIGGER A8

Event trigger source

EVN_ON_LEVEL A8

Trigger activation level in dB (10 ÷ 140, default: 90)

EVN_OFF_LEVEL A8

Trigger deactivation level in dB (10 ÷ 140, default: 60)

EVN_POLARITY A8

Trigger level polarity (POS/NEG)

EVN_ON_TIME A8

Trigger activation delay in seconds from 0 to 10

EVN_OFF_TIME A8

Trigger deactivation delay in seconds from 0 to 255

EVN_PRINT A8

Enabling event trigger printing

AUTO_STORE A8

Enabling Auto-Store function (ON/OFF, default: OFF)

SLM+PROF_DLOGGER A8

Continuous recording of SLM and PROFILE parameters (ON/OFF, default: ON

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Command Format Description

1_REP_PARAMETER A6

REPORT parameter 1 (see parameter list)

2_REP_PARAMETER A6

REPORT parameter 2 (see parameter list)

3_REP_PARAMETER A6

REPORT parameter 3 (see parameter list)

4_REP_PARAMETER A6

REPORT parameter 4 (see parameter list)

5_REP_PARAMETER A6

REPORT parameter 5 (see parameter list)

REP_PARAMETERS A8

Recording of REPORT parameters 1-5 (ON/OFF, default: OFF)

REP_OCTAVE A8

Recording of Octave spectrum (ON/OFF, default: OFF)

REP_TOCTAVE A8

Recording of Third Octave spectrum (ON/OFF, default: OFF)

REP_STATISTICS A8

Statistical recording (ON/OFF, default: OFF)

1_EVN_PARAMETER A6

EVENT parameter 1 (see parameter list)

2_EVN_PARAMETER A6

EVENT parameter 2 (see parameter list)

3_EVN_PARAMETER A6

EVENT parameter 3 (see parameter list)

4_EVN_PARAMETER A6

EVENT parameter 4 (see parameter list)

5_EVN_PARAMETER A6

EVENT parameter 5 (see parameter list)

EVN_PARAMETERS A8

Recording of EVENT parameters 1-5 (ON/OFF, default: OFF)

EVN_OCTAVE A8

Recording of Octave spectrum (ON/OFF, default: OFF)

EVN_TOCTAVE A8

Recording of Third Octave spectrum (ON/OFF, default: OFF)

EVN_STATISTICS A8

Statistical recording (ON/OFF, default: OFF)

CAL_LEVEL A8

Acoustic calibrator level in dB (90.0 ÷ 130.0, default: 94.0)

MIC_CORR A8

Acoustic range correction

WND_SHL_CORR A10

Wind-shield correction (ON/OFF, default: OFF)

SEQ_TIMER A3

Acquisition dela y in s, m (1÷59) or h (1÷99)

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The value that some parameters can take is listed in the following table (default value in bold print).

Parameter Value

BAUD_RATE

300 600

1.2

2.4

4.8

9.6

19.2

38.4

57.6

115.2

230.4

DEVICE

RS232

MODEM

USB

PRINTER

INPUT_GAIN

20 30 40

ERASE_TIME

10s 30s 60s

INT_MODE

SIN

MULT

REPORT_TIME

5s 10s 20s 30s

m2m5m10m

SPECT_AUX_POND

EVN_TRIGGER

OFF LEV

MAN

MIC_CORR

WND_SHL_CORR

OFF SAV

WME

EVN_PRINT

OFF

TAG

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The parameters that can be displayed in SLM mode are selectable among the following ones:

Parameter Attribute Description

Lpk Z or C Instantaneous peak level, Z or C weighted Lpkmx Z or C Peak maximum level LeqS Z, C or A Short equivalent level, Z, C or A weighted Leq Z, C or A Equivalent sound pressure level LFp Z, C or A FAST sound pressure level LSp Z, C or A SLOW sound pressure level LIp Z, C or A IMPULSE sound pressure level LFmx Z, C or A FAST maximum sound pressure level LSmx Z, C or A SLOW maximum sound pressure level LImx Z, C or A IMPULSE maximum sound pressure level LFmn Z, C or A FAST minimum sound pressure level LSmn Z, C or A SLOW minimum sound pressure level LImn Z, C or A IMPULSE minimum sound pressure level LeqI A Equivalent sound pressure level with Impulse time constant LE A A weighted exposure level (SEL) Dose A A weighted dose Dose,d A A weighted daily dose L1 A Percentile level (calculated on FAST pressure level, A weighted) L2 A Percentile level L3 A Percentile level L4 A Percentile level OL - Time percentage in which an overload has occurred

The attribute of parameters that can be displayed in SLM mode indicates the respective frequency weighting.

KEY GROUP

The following table shows the command list of the KEY group.

Command Format Description

LEFT C1 LEFT key

MENU C1 MENU key

PRINT C1 PRINT key

PROG C1 PROG key

PAUSE C1 PAUSE key

RUN C1 RUN key

SELECT C1 SELECT key

UP C1 UP key MODE C1 MODE key RIGHT C1 RIGHT key

ENTER C1 ENTER key DOWN C1 DOWN key

HOLD C1 ALPHA key

CURSOR C1 HOLD key

CLEFT C1 CURSOR key

CRIGHT C1 CURSOR LEFT key

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Command Format Description

SER_MON C1 CURSOR RIGHT key

STORE C1 Simulates the PRINT key to be pressed for more than 2 sec

DATA_LOG C1 Simulates the REC key to be pressed for more then 2 sec

PRN_VAL C1 REC+RUN key

EXEC C2 PRINT key without printing the heading

STT GROUP (STATUS)

The following table shows the command list of the STT group (STATUS).

Command Description

ACQUISITION Acquisition control

DISPLAY Display management

MONITOR Monitor function via RS232

RECORDER Recording management

The STT:ACQUISITION commands are provided in the following table.

Command Format Description

HOLD D1 Interrupts display update

UPDATE D1 Restarts display update

PAUSE D1 Measurement in pause

RUN D1 Starts measurements

STOP D1 Ends measurements

CLEAR D1 Clears measured levels

CONTINUE D1 Restarts measuring

ERASE D1 Erases the last x seconds of measurements

RECORD D1 Starts and records measurements

The STT:ACQUISITION:? command provides information on the acquisition status as shown in the following example.

STT:ACQ:?

STT:ACQUISITION:STOP BATTERY: 32% MEMORY: 95.4% DUMP TIME:00:00:01 LAST CALIBRATION: 2003/07/31 08:37

The STT:DISPLAY commands are listed in the table below.

Command Format Description

SLM D1 Displays 5 selectable parameters in numeric format PROFILE D1 Displays the time profile of a selectable parameter OCTAVE D1 Displays the spectrum by octave bands

THIRD_OCTAVE D1 Display the spectrum by one-third octave bands

PROB_DISTR. D1 Displays the level distribution of probabilities

CUMUL_DISTR. D1 Displays the percentile levels graph

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The STT:DISPLAY:? command provides information relevant to the sound level meter actual display as shown in this example:

STT:DIS:?

STT:DISPLAY:Mode:PROFILE

The following table lists the STT:MONITOR commands.

Command Format Description

ON D1 Starts the Monitor function

OFF D1 Ends the Monitor function

MEASUREMENT D1 Monitor

SLM D1 Monitor by 3 parameters PROFILE D1 Monitor by single parameter OCTAVE D1 Monitor of the spectrum by octave bands

THIRD_OCTAVE D1 Monitor/Recording by third octave bands

REPORT D1 Monitor of the reports

EVENT D1 Monitor of the events

The following table lists the STT:RECORDER commands.

Command Format Description

ON D1 Starts the Record function

OFF D1 Terminates the Record function

AUTO D1 Enables the Auto-Store function

STT:MONITOR:? and STT:RECORDER:? commands provide information on the monitor and recording status as shown in the following example.

STT:REC:?

STT:RECORDER:Measurement:SLM:OFF

DMP GROUP (DUMP)

The table below features the list of the DMP group commands (DUMP).

Command Format Description

ON E1 Starts memory dump

OFF E1 Ends memory dump

NEXT_RECORD E1 Requires the transmission of the next record

RECORD E1 Requires the transmission of the current record

CLEAR E1 Clears memory

Data download sequence is:

•

DMP:ON\r\n

The heading ending in the string “MEMORY DUMP\r\n” is printed if there are any data on

memory

•

DMP:RECORD\r\n

Prints the previous record in binary format

•

DMP:NEXT_RECORD\r\n

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Prints the current record in binary format. If this is the last record, it prints the string “END

OF DUMP\r\n”

•

DMP:CLEAR\r\n (optional)

Clears memory

•

DMP:OFF\r\n

Ends data dump

Data dump can be interrupted through the sequences:

•

DMP:OFF\r\n

Ends data dump

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CONNECTION TO A MODEM

A modem connection allows a remote control of the HD2010UC/A sound level meter. Optional

Noise Studio module “Monitor” for PC, can fully manage the sound level meter not only via a

simple RS232 serial connection or USB, but also, via the telephone line by means of two modems.

While the modem that connects the PC to the telephone line must not meet any particular requirement but being Hayes© compatible, the modem connected to the HD2110 sound level meter has to be configurable by the sound level meter itself and shall not interfere with improper messages during the delicate data transmission phase from the sound level meter to the PC. Delta Ohm s.r.l. suggests three types of modems to be used:

 Multitech MT2834ZDX

 Digicom SNM49

 Digicom Botticelli

The connection with these modems has been tested. Other modems might be used but, due to the great variety available on the market, we cannot provide service for the connection to modems other than those listed here.

The modem connected to the HD2010UC/A sound level meter must be configured before being used for data transmission. The configuration is carried out automatically by the sound level meter itself, according to the following steps.

Connect the modem to the HD2010UC/A by means of the HD2110CSM special cable with

M12 connector.

Connect the modem to the telephone line and the power supply.

Switch on the modem.

Switch on the sound level meter.

Set the baud rate at 38400 baud at least via the parameter: MENU >> Instrument >> In-

put/Output >> RS232 Baud Rate.

Select MODEM as serial connection through the parameter: MENU >> Instrument >> In-

put/Output >> Serial Device.

The instrument automatically gets into the modem configuration mode. The successful configuration will be confirmed by the message “Modem Configured.” Should the configuration fail, the sound level meter will automatically switch to PC mode and the message “Configuration failed!” will be displayed.

When the modem is configured, it is possible to make the remote connection running

Noise

Studio “Monitor”

module. Possible under voltages on the modem do not create problems as the configuration is memorized and automatically loaded on turning it on. The table shows the HD2110CSM cable connections:

M12 connector (female 8-pole) DB25 serial connector (male)

1 5 2 20 3 8 4 22 5 3 6 4 7 2 8 7

HD2010UC/A - 87 - V4.1

Connectors – front/external view

DB25 M12

CONNECTION TO A PRINTER

The HD2010UC/A sound level meter can print the levels displayed in a format compatible with a portable 24 column printer, such as the HD40.1.

Printer and sound level meter must be configured properly.

Sound level meter configuration

1. Set the parameter MENU >> Instrument >> In-

put/Output >> RS232 Baud Rate to: 38.4k

Set the parameter MENU >> Instrument >> In-

put/Output >> Serial Device to: PRINTER.

Printer configuration

1. The printer Baud Rate must be the same of the

sound level meter (38400 baud).

Data bits: 8.

Parity: None

Stop bits: 1.

Handshaking: Xon/Xoff

Autofeed: Enabled.

Connect the HD2010UC/A sound level meter to the printer by means of the special

HD2110RS ca-

ble. Follow the instructions in the documentation supplied with the printer.

HD2010UC/A - 88 - V4.1

CONNECTION TO A PC WITH USB INTERFACE

The HD2010UC/A sound level meter fitted with USB interface can be connected to a PC’s USB port by using the HD2110USB cable.

The USB port connection requires the previous installation of a driver contained in the Noise Studio software.

Before connecting the USB cable to the PC, install the Noise Studio software.

With Windows 7 operating systems it’s necessary to boot the PC disabling the request for driver signature, as explained in the USB driver’s installation guide included in the Noise Studio CDRom.

Proceed as follows:

Set the instrument menu item “MENU >> Instrument >> Input/Output >> Serial Device” to

“USB”. Confirm and exit from the menu”.

2. Do not connect the instrument to USB port until requested from the wizard

3. Insert Noise Studio installation CDRom and wait for AutoPlay window to appear. In Win-

dows Vista and Windows 7 operating systems it’s shown the window below; select “auto-

run.exe execution” (see “note 1” in the next paragraph)

The starting screen of Noise Studio will be opened: if the operating system prevents software

to start, please see “note 1” in the next paragraph.

From starting window of Noise Studio click on “USB drive installation” to start the driver in-

stallation procedure.

The program checks the Windows

operating system version and copies related drivers in a

temporary folder.

At the end a message appears asking to plug the sound level meter connection cable to PC

USB port: press OK and close

Noise Studio software pressing EXIT key.

Connect the sound level meter to USB port and turn it ON: when Windows recognise the

instrument, it appears a message “ a new device has been detected”.

Wait some seconds until the message “new hardware is installed and ready to work” appears.

10.

Driver installation procedure is ended: whenever the instrument will be connected it will be

automatically recognized.

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INSTALLATION NOTES

Note 1: for Windows Vista and Windows 7 operating systems.

1. For software installation is requested Administrator permission

If the operating system prevents the software to open, boot the PC as administrator, insert in-

stallation CDRom and, when the following window appears, select “open folder to view files”

In the following screen, click with right mouse key on file “Autorun” and select “Execute as ad-

ministrator”:

Continue from point 5 of previous paragraph.

Note 2: if the sound level meter has been connected to USB port before USB driver installation,

in Windows 2000 and XP operating systems it appears the window “new hardware installation”. In Windows Vista and Windows 7 it appears an installation error under “device manager”: in both cases, cancel operation, disconnect instrument and restart the complete procedure starting from the beginning of this guide.

VERIFICATION OF PROPER DRIVER INSTALLATION

To verify the proper installation procedure, proceed as follows.

On Windows 2000 and XP operating systems:

Select “START >> Settings >> Control Panel”, double click on SYSTEM icon. Select

“Hardware >> Device Manager”

On Windows Vista and Windows 7 operating systems:

Select “START >> Control panel”, then click on “Device Manager” icon.

Connect instrument to USB port.

The following items should appear:

•

“Port (COM and LPT) >> USB Serial Port (COM#)”. The value # is the number assigned

to virtual serial port.

• “Controller USB (Universal serial bus) >> USB serial converter”

HD2010UC/A - 90 - V4.1

When USB cable is unplugged, the above items will disappear and they will appear again as soon as the instrument is plugged to USB port.

In the documentation supplied with the

Noise Studio CDRom, it’s available a detailed version (in-

cluding images) of the USB driver management guide.

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HD2010MC MEMORY CARD READER

The reader HD2010MC can be used on the sound level meters provided with M12 serial connection. Sound level meters not provided with M12 input, can be modified in order to be able to use the memory card reader HD2010MC.

DESCRIPTION OF THE INTERFACE FOR MEMORY CARD HD2010MC

The reader HD2010MC allows to expand the storage capacity of the sound level meter. By employing SD type or MMC card type, it is possible to record, for example, a sound level profile continuously for several months. In addition, it is possible to download data from the internal memory of the sound level meter to the card. This function can turn very useful when the effected measurements need to be downloaded without moving the device or without using a notebook.

The maximum storage capacity of the card is 2GB, the formatting is FAT16 type.

The reader is powered by the sound level meter and doesn’t require any external power supply.

PREPARATION OF A NEW MEMORY CARD

Every new memory card needs to be formatted before use by means of the appropriate function of the Noise Studio software. The formatting function requires the PC, on which the Noise studio Software has been installed, to be equipped with a PC Memory card reader (not included in supply). Those are typically included in most recent laptops and desktop computers. Optionally it is possible to use an external memory card, to be connected to an USB port.

How to format a memory card:

1. If the PC isn’t provided with a SD/MMC card reader, connect an external device to the USB

port of the PC.

Start up the Noise Studio software.

Press the key Instrument management in Noise Studio: press the key Memory Card Format-

ting.

Select the path of the card to be formatted and confirm with ENTER.

On the following screen, ensure that the parameter “File System = FAT” has been selected

and press START: the card will be formatted.

HD2010UC/A - 92 - V4.1

6. When the message “Formatting completed” appears, press OK for confirmation and CLOSE

to exit.

Close the Noise Studio software.

The formatting has been accomplished and the card is ready for use.

CONNECTION OF HD2010MC TO THE SOUND LEVEL METER AND USE OF THE MEMORY CARD

Connection of the HD2010MC:

1. Switch off the sound level meter .

Connect HD2010MC to the M12 connector of the sound level meter ensuring the correct fas-

tening of the connector’s ring nut.

While inserting, please make sure that the arrow printed

on the reader is turned upwards. The reader has to be connected to the sound level meter in

vertical position.

Insert the memory card in the slot of HD2010MC interface.

Switch on the sound level meter and set the menu item “MENU >> Instrument >> Input/Output

>> Serial device ” on “MC”.

The sound level meter identifies the device. The display of the sound level meter shows “MC

connected” and the remaining dimension of memory. The LED on the card reader signalizes the connection.

If the display visualizes “Connection failed”, check carefully if the memory card has been in-

troduced correctly into the slot and if the connector is plugged in properly.

When HD2010MC interface is connected to the sound level meter, any recording is automatically sent to the memory card rather than to the internal memory of the sound level meter.

During recording, the LED on the reader flashes upon receipt of every data package. When memory is used up entirely, the recording will be interrupted.

To disconnect HD2010MC interface from the sound level meter:

1. Switch off the sound level meter.

Disconnect HD2010MC interface.

NOTE: Slipping off the memory card while the sound level meter is running and interface is connected causes the loss of all data. In order to replace the memory card, switch off the sound level meter.

HD2010UC/A - 93 - V4.1

For disabling HD2010MC temporarily:

Set the menu item “MENU >> Instrument >> Input/Output >> Serial device” on a different device than MC. In order to re-enable the reader, set the menu item on “MC”.

FOR USING DATA DIRECTLY FROM PC

In order to read and copy files from the memory card to the PC, use a memory card reader for PC: the card will be recognized as external peripheral mass storage device. Do not write, cancel or modify the files through the PC. In order to cancel the memory card, use the formatting function (see chapter “Preparation of a new memory card”).

DATA TRANSFER FROM SOUND LEVEL METER TO MEMORY CARD

Data can be transferred from the internal memory of the sound level meter to the external memory by executing the sound level meter program “PROG key >> Data download to MC”. This program allows copying of the measurements recorded in the sound level meter into the external memory card. The program can be activated only after having connected the memory card interface HD2010MC, as described in the chapter “Connection of HD2010MC to the sound level meter and use of the memory card”. During data download, which occurs automatically, the remaining memory space of the card and the estimation of program completion time are displayed on the screen. The data transfer from the sound level meter to the memory card

doesn’t delete the internal mem-

ory of the sound level meter. I order to delete the content of the internal data memory of the sound level meter, it is necessary to use the Navigator program.

To cancel the data of the card, use only the formatting function of Noise Studio: the erasure of single files contained in the memory card is not foreseen.

The Navigator program is not able to manage registrations which have been effected with external devices as interface for HD2010MC memory card.

TECHNICAL SPECIFICATIONS

Type of card MMC and SD Maximum capacity 2GB Power supply provided by sound level meter Function indicator LED on the reader Connector 8-pole female M12

HD2010UC/A - 94 - V4.1

TECHNICAL SPECIFICATIONS

The HD2010UC/A sound level meter is a type 1 or 2 integrating sound level meter with frequency analysis by octave and third octave bands (

with “Third Octave” option), as well as with statistical

analysis.

HD2010UC/A complies with the following standards

 IEC 61672:2002-5 Class 1 or Class 2 Group X  IEC 60651:2001-10 Class 1 or Class 2  IEC 60804:2000-10 Class 1 or Class 2  IEC 61260:1995-8 Class 1 + Amendment 1:2001-09  ANSI S1.4:1983 Type 1 o Type 2  ANSI S1.11:1986 Order 3 Type 1-D Optional Range

Microphone Models

 UC52, ½ inch pre-polarized microphone with 20 mV/Pa sensitivity; frequency response op-

timized for Free Field.

 MC24E and MC24EH, ¼ inch with 2 mV/Pa (MC24E) or 0.25 mV/Pa (MC24EH) sensitiv-

ity, pre-polarized, optimized for free field measurements.

Preamplifier Models

For ½ inch pre-polarized microphones, with 20 mV/Pa sensitivity:

 HD2010PNE2: with connection for UC52, ½” microphone and driver for extension cable up

to 10mt. This preamplifier is provided with CTC device for electrical calibration, it can be di-

rectly plugged into the HD2010UC o using the extension cable..

 HD2010PNE2W: heated preamplifier with connection for UC52, ½” microphone and driver

for extension cable. This preamplifier is provided with CTC device for electrical calibration,

it can be plugged into the sound level meter o using the 5mt extension cable provided (10mt

as an option).

Suitable for ¼ inch microphones

 HD2010PNE4: preamplifier for MC24E ¼” microphone. Equipped with CTC calibration de-

vice for electric calibration and driver for cable up to 100m. Requires the HDP079A02 mi-

crophone adapter.

 HD2010PNE4H: preamplifier for MC24EH ¼” microphone. Equipped with CTC calibration

device for electric calibration and driver for cable up to 100m. Requires the HDP079A02 mi-

crophone adapter.

Accessories

The use of the following accessories does not significantly modify the HD2010UC/A technical specifications:

 HD SAV Windshield (with spectral correction Menu >> Calibration >> Shield >> SAV for

type 1 version)

 HDP079A02 microphone adapter for ¼ microphones, for the use of MC24E microphone with

HD2010PNE4 preamplifier and MC24EH microphone with HD2010PNE4H preamplifier.

 Extension cable between the preamplifier and the body of the sound level meter up to a

maximum of 10m.

 Stabilized power supply SWD10.  Portable thermal printer HD40.1.  VTRAP tripod and HD2110/SA support for the preamplifier  Outdoor protection HD WME: (with spectral correction Menu >> Calibration >> Shield >>

WME for type 1 version)

 HD2010MC memory card reader.

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METROLOGICAL CHARACTERISTICS

Frequency Weighting

 A, C, Z for RMS measurements  C, Z for peak level measurements  Filters with bandwidth corresponding to an octave from 31.5 Hz to 8 kHz.  Filters with bandwidth equal to third octave (with “Third Octave” option) from 25 Hz

to12.5 kHz.

Z weighting is flat along the whole sound spectrum with the following features:

Attenuation

[dB]

Frequency Range

[Hz]

< 0.1 100 ÷ 20 k

< 1 31.5 ÷ 21 k < 5 16 ÷ 22.5 k

Filters with bandwidth equal to an octave or third of octave are all class 1 filters according to IEC

61260.

Frequency Response

Response/dB

Frequenc y / Hz

The selection of the UC52 microphones, on the basis of frequency response specifications, and the spectral corrections calculated by the sound level meter DSP allows obtaining a Class 1 response according to IEC61672:2002. The HD2010UC/A is also available in the Class 2 version.

The frequency response of the microphone depends on the presence of devices like windshield HD SAV or all-weather protection unit HD WME. In order to make measurements with the maximum possible precision in different situations, the HD2010UC/A sound level meter can automatically apply spectral corrections needed to measure in random field conditions, or with the windshield or with the all-weather outdoor protection. Spectral correction for diffuse field measurement is enabled setting parameter Menu >> Calibration >> Mic.Resp.Correction >> RI while correction for HD SAV mounted, is enabled setting parameter Menu >> Calibration >> Shield >> SAV.

For more information on the applied corrections please refer to the UC52 microphone manual.

1. Tolerance +

2. Sound level meter response

3. Microphone response

4. Tolerance –

5. Effect of the case

(

dotted line

)

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Outdoor microphone protection HD WME

The windshield and rain protection units mounted on HD WME outdoor protection, modify

microphone frequency response: in order to apply the correction to sound level meter overall re-

sponse, it’s necessary to set the specific parameter Menu >> Calibration >> Shield >> WME.

With this setting applied, HD2010UC/A sound level meter with HD WME protection, fully

complies to type 1 specifications according to IEC 61672 standard; in such configuration, when

used in vertical position, the sound level meter is able to measure accurately environmental noise

from above (0° incidence) like for example the noise generated by aircraft over flights.

When parameter Menu >> Calibration >> Shield is set to WME and microphone acoustic response (menu Calibration >> Mic.Resp.Correction) is set to RI, it’s applied a frequency spectral correction to obtain a flat frequency response in a diffuse field. Using this setting the HD2010UC/A sound level meter with HD WME outdoor protection mounted in vertical position, is suitable for measurements of environmental community noise due to noise sources on the ground (road traffic noise, railway noise…).

For more information on spectral correction applied to HD2010UC/A sound level meter when used with HD WME outdoor protection, please refer to UC52 microphone user manual.

Self-generated Noise

The intrinsic noise (measured replacing the microphone with the capacitive adapter) is shown in the following tables according to the different frequency weightings, either for

RMS level or

peak level measurements:

Input Gain

[dB]

intrinsic noise [dB]

LpA LpC LpZ LpkC LpkZ

50 49 53 61 65

40 39 43 51 55

31 32 36 45 48

26 30 33 43 45

24 29 33 43 45

The intrinsic noise, by constant percentage bandwidth, both octave and third octave, is given in the following tables:

Input Gain

[dB]

intrinsic noise by octave bands [dB]

32 63 125 250 500 1k 2k 4k 8k

24 31 19 18 18 19 15 16 17

Input Gain

[dB]

intrinsic noise by third octave bands [dB]

25 31.5 40 50 63 80 100 125 160 200 250

20 19 15 9 9 8 8 8 8 8 9

Input Gain

[dB]

intrinsic noise by third octave bands [dB]

315 400 500 630 800 1k 1.25k 1.6k 2k 2.5k 3.15k

9 13 13 12 12 17 11 10 10 11 11

Input Gain

[dB]

intrinsic noise by third octave bands [dB]

4k 5k 6.3k 8k 10k 12.5k

11 11 12 12 13 13

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Linearity range

The lower limit of the linearity range, by constant percentage bandwidth, can be taken by the intrinsic noise table and adding 7 dB. The upper limits correspond to 141 dB and 131 dB, respectively for input gain equal to 0 dB and 10 dB. The linearity range is almost independent of frequency in the 31.5 Hz … 12.5 kHz interval, and it is shown in the following table according to the input gain:

Input Gain [dB] Parameter

Lower Limit

[dB]

Upper Limit

[dB]

LpA

141

LpC

LpZ

LpkC

68 144

LpkZ

LpA

131

LpC

LpZ

LpkC

58 134

LpkZ

LpA

121

LpC

LpZ

LpkC

52 124

LpkZ

LpA

111

LpC

LpZ

LpkC

50 114

LpkZ

LpA

101

LpC

LpZ

LpkC

50 104

LpkZ

The starting level for the linearity range detection matches the reference level (94 dB) at 1 kHz.

With different frequencies, the starting level takes into account the attenuation of the frequency weighting being measured. In the secondary fields the starting level is subject to the same increment of the input gain.

Integration Time

It can be set from a minimum of 1s to a maximum of 99 hours.

Measurement Dynamics with Electromagnetic Fields

Minimum measurable level equal to 60dBA with carrier from 26 MHz to 1 GHz and amplitude equal to 10V/m modulated 80% at 1 kHz.

Reference Conditions

 The measuring range is that with input gain equal to 10 dB.  The level corresponds to 94 dB.

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 The acoustic calibration can be performed at a sound level included in the range 94dB ÷

124dB.

 The reference direction of the acoustic signal is that of the preamplifier longitudinal axis.  The reference acoustic field is the free field

Operating conditions

 Storage temperature: -25 ÷ 70°C.  Operating temperature: -10 ÷ 50°C.  Working relative humidity: 25 ÷ 90%RH, not condensing.  Static pressure: 65 ÷ 108kPa.  Protection degree: IP64.

In case of condensation growth, it must evaporate completely before using the sound level meter.

Drifts

 Temperature: ± 0.3 dB over the range -10 ÷ 50°C (with correction for microphone drift acti-

vated).

 Relative humidity: ± 0.3 dB over the range 25 ÷ 90%RH, not condensing.  Static pressure: ± 0.3 dB over the range 65 ÷ 108kPa.

ELECTRICAL CHARACTERISTICS

Pre-heating time

Less than 10 seconds.

Power Supply

 Batteries: 4 alkaline or rechargeable AA 1.5V internal batteries. The sound level meter does

not include a battery charger.

 Autonomy: >12 hours in RUN mode with alkaline good-quality batteries. Amounting to 8

hours when using the outdoor microphone unit HD WME fitted with heated preamplifier.

 External batteries: It is possible to connect external batteries to the sound level meter through

the male connector for external power supply (∅ 5.5mm socket). The positive (pole) power

supply must be connected to the central pin. The battery should supply 9 ÷ 12V at about

200mA/h. The maximum limit for external power supply is 15V.

 Mains: mains adapter with 9 Vdc/300mA continuous voltage.  Switch-off: selectable auto-power-off.

When battery voltage falls below 3.9V, the sound level meter cannot perform any measurement. However it is possible to access and download the data in the memory. Under 3.5V, the instrument will automatically shut off. Logged data and configuration parameter are maintained even without power supply.

Input maximum levels

The maximum tolerable sound level with UC52 microphone is 146 dB.

The level of the electrical signal applicable to the microphone input, despite the replacement of the microphone capsule with the proper capacitive adapter, must not exceed 10Vrms.

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LINE Output

 3.5mm ∅ mono jack  Preamplifier output signal  Non-weighted output protected against short-circuit  Gain: ~ 3 mV/Pa and ~ 30 mV/Pa respectively for an input gain equal to 0 dB and 20 dB, not

calibrated

 Linearity: 100dB with output maximum level equal to 2Vrms  Series impedance: 1kΩ  Typical Load: 100kΩ

DC Output

 2.5mm ∅ mono jack  Short-circuit protected output  A weighted output with FAST constant time updated 8 times/s  Gain: 10 mV/dB Linearity: 80 dB  Series impedance: 1kΩ  Typical Load: 100kΩ

Serial interface

 Socket: 8-way M12  Type: RS232C (EIA/TIA574) not insulated  Baud rate: between 300 and 230400 baud  Data bits: 8  Parity: None  Stop bits: 1  Flow control: Hardware  Cable length: max 15m

Extension Cable for the Microphone

The microphone preamplifier can be connected to the body through an extension cable up to

10m long (CPA). The sound level meter specifications are not significantly modified by the

cable presence.

STATISTICAL ANALYSIS

Descriptors L

AFp

or Leq Short or Lpk

Sampling 1/8 s.

Classes from 0.5 dB.

Measurement range: 30dB ÷ 140dB.

4 percentile levels, programmable between L

to L

99.

Statistical graphs calculation and display .

Graph of the level distribution of probabilities

Graph of the percentile levels from L

to L

99.

SPECTRAL ANALYSIS

Sampling: 48 kHz

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Reference Attenuation: 0dB

Reference Range: 50dB ÷ 130dB

Reference Level: 94dB

Octave bands from 31.5 Hz to 8kHz

Third Octave bans from 25Hz to 12.5kHz (option HD2010.O1)

Spectrum frequency weighting (only display): linear (Z) , C or A.

Ratio of filter central frequencies: base 2

Average spectra with sampling time equal to 0.5s, linearly integrated up to a maximum of 99 hours.

Multi-spectral analysis in 1 second intervals up to 1 hour (“Report” recording)

REVERBERATION TIME MEASUREMENT (OPTIONAL)

Reverberation time calculation by sound source interruption with guided wizard

Reverberation time calculation by applying (Schroeder’s inverse Integral) the impulse response technique and background contribution correction algorithm.

Frequency Range: octave from 125 Hz to 8 kHz and optional third of octave from 100 Hz to 10 kHz.

Spectrum Step: 32 spectra per second.

Measurement dynamic: 80dB.

Optimized interpolation of the decay profile, with correlation coefficient calculation using the Ordinary Least Squares method.

Simultaneous calculation of: EDT, T(10), T(20), T(30) estimations of the reverberation time T

according to ISO 3382 standard.

Calculation of T

directly on the decay profile over an interval selected by the user positioning

the cursors.

VISUALIZATION

Graphic display

Backlit 128x64 pixels on a 56x38mm surface.

Mode:

 SLM (sound level meter) screen with 3 selectable parameters.  Time profile of the A weighted sound pressure level with FAST time constant according to

1/8s intervals.

 Octave band spectra between 31.5 Hz and 8 kHz and third octave spectra between 25 Hz and

12.5 kHz.

 Level distribution of probabilities in 0.5dB, 1dB or 2dB classes.  Graph of the percentile levels from L1 to L99.

Display mode for the reverberation time measurement

 Numeric screen providing the chosen band:

source maximum level

background noise level of the environment

EDT, T(10), T(20), T(30)

DeltaOHM HD2010UC/A Operating Manual

Specifications and Main Features

Frequently Asked Questions

User Manual