HT instruments HT157 User Manual
User manual
HT155 – HT157
Copyright HT ITALIA 2011 Release EN 1.02 - 28/12/2011
HT155 - HT157
Table of contents:
1. PRECAUTIONS AND SAFETY MEASURES .................................................................. 3
1.1. Preliminary instructions .................................................................................................... 3
1.2. During use ........................................................................................................................ 3
1.3. After use ........................................................................................................................... 3
2. GENERAL DESCRIPTION .............................................................................................. 4
3. PREPARATION FOR USE .............................................................................................. 5
3.1. Initial inspections .............................................................................................................. 5
3.2. Instrument power supply .................................................................................................. 5
3.3. Calibration ........................................................................................................................ 5
3.4. Storage ............................................................................................................................. 5
4. OPERATING INSTRUCTIONS ........................................................................................ 6
4.1. Instrument description ...................................................................................................... 6
4.1.1. Front panel .................................................................................................................... 6
4.1.2. Output interface ............................................................................................................. 6
4.2. Description of function keys ............................................................................................. 7
4.3. Analogue output description............................................................................................. 7
4.4. Display contrast adjustment ............................................................................................. 8
4.5. Turning ON/OFF the instrument ...................................................................................... 8
4.6. Configuration of measuring parameters ........................................................................... 9
4.6.1. Foreword ....................................................................................................................... 9
4.6.2. Programming menu interface ........................................................................................ 9
4.6.3. Defining the measure name ........................................................................................ 11
5. CARRYING OUT MEASUREMENTS ............................................................................ 13
5.1. Statistic analysis of noise ............................................................................................... 13
5.1.1. Initial operations .......................................................................................................... 13
5.1.2. Statistic analysis operations ........................................................................................ 14
5.1.3. 24-hour analysis operations ........................................................................................ 17
5.1.4. Integration analysis operations .................................................................................... 21
5.2. Noise analysis in 1/1 and 1/3 octave band (HT157 only)............................................... 24
5.2.1. Initial operations .......................................................................................................... 24
5.2.2. Octave band analysis (1/1) .......................................................................................... 25
5.2.2.1. Operations for sections LIST, GRAPH and TOTAL ................................................... 25
5.2.3. Analysis in third-octave band (1/3) .............................................................................. 30
5.2.3.1. Operations for sections LIST, GRAPH ....................................................................... 30
5.2.3.2. Operations in TOTAL section ..................................................................................... 33
6. INSTRUMENT ACOUSTIC CALIBRATION ................................................................... 35
6.1.1. Foreword ..................................................................................................................... 35
6.1.2. Preliminary operations ................................................................................................. 35
6.1.3. Acoustic calibration with calibrator HT151 .................................................................. 37
6.1.3.1. Replacing the calibrator battery ................................................................................. 38
6.1.3.2. Calibration result display ............................................................................................ 39
6.1.4. Direct acoustic Calibration ........................................................................................... 39
7. OPERATIONS WITH THE MEMORY ............................................................................ 40
7.1. Recalling results on the display...................................................................................... 40
7.1.1. Recalling the statistic analysis data on the display ..................................................... 41
7.1.2. Recalling the 24H analysis data on the display ........................................................... 42
7.1.3. Recalling the integration measurement data on the display ........................................ 44
7.1.4. Recalling the data of the octave band analysis (1/1) on the display ........................... 45
7.1.4.1. Recalling the data of the analysis in Total octave band (1/1) ..................................... 46
7.1.5. Recalling the data of the analysis in third-octave band (1/3) on the display ............... 47
7.2. Data transfer onto USB Pen Drive ................................................................................. 48
8. OPERATIONS WITH SOUNDVIEW SOFTWARE ......................................................... 49
EN - 1
HT155 - HT157
8.1. Foreword ........................................................................................................................ 49
8.2. Minimum system requirements ...................................................................................... 49
8.3. Installing the driver USB ................................................................................................. 49
8.4. Use of SoundView software ........................................................................................... 51
8.4.1. Copy and Print commands .......................................................................................... 51
8.4.2. File menu ..................................................................................................................... 52
8.4.3. View menu ................................................................................................................... 53
8.4.4. Name Menu ................................................................................................................. 53
8.4.5. Result menu ................................................................................................................ 54
8.4.6. Calibration menu ......................................................................................................... 54
8.4.7. Help menu ................................................................................................................... 54
9. MAINTENANCE ............................................................................................................ 55
9.1. General information ........................................................................................................ 55
9.2. replacing the batteries .................................................................................................... 55
9.3. Cleaning the instrument ................................................................................................. 55
9.4. End of life ....................................................................................................................... 55
10. TECHNICAL SPECIFICATIONS ............................................................................. 56
10.1. Technical specifications .......................................................................................... 56
10.2. Statistic analisys chararcteristics ............................................................................ 57
10.3. Characteristics of analysis in 1/1 and 1/3 octave band (HT157 only) .................... 57
10.4. Characteritics of portable calibrator HT151 ............................................................ 57
10.5. General characteristics ........................................................................................... 58
10.6. Accessories ............................................................................................................ 58
11. SERVICE ................................................................................................................ 59
11.1. Warranty conditions ................................................................................................ 59
11.2. Service .................................................................................................................... 59
12. APPENDIXES ......................................................................................................... 60
12.1. Appendix 1 – Frequency weighting characteristics ................................................ 60
12.2. Appendix 2 – characteristics of 1/3 octave band filter ............................................ 61
12.3. Appendix 3 – frequency weighting A, C ................................................................. 64
12.4. Appendix 4 – characteristics of 4Hz high-pass digital filter .................................... 65
EN - 2
HT155 - HT157
A
1. PRECAUTIONS AND SAFETY MEASURES
The instrument has been designed in compliance with the directives regarding electronic
measuring instruments. For your safety and to prevent damaging the instrument, we
recommend following the procedures described in this manual and carefully reading all
notes preceded by the symbol .
Before and during measurements, carefully observe the following instructions:
Do not perform any measurement in humid environments.
Do not perform any measurement in the presence of gas, explosive or flammable
material, or in dusty areas.
Do not perform any measurement when anomalies are found in the instrument, such as
deformations, breaks, substance leaks, no display view, etc.
In this manual and on the instrument, the following symbols are used:
Warning: observe the instructions reported in the manual. An improper use could
damage the instrument or its components.
Instrument complying with the standards relevant to the EC mark
1.1. PRELIMINARY INSTRUCTIONS
CAUTION
The instrument has been designed for measuring sound pressure levels
(SPL) from 25dB to 140dB with frequency ranging from 10Hz to 20kHz
We recommend following the usual safety rules to protect the instrument
against improper use
After a long storage period or if the instrument has been used under critical
conditions, recalibrating the instrument is recommended (see § 6)
Check if the batteries are correctly inserted
1.2. DURING USE
We recommend carefully reading the following recommendations and instructions:
CAUTION
Failure to observe the warnings and/or instructions may damage the
instrument and/or its components or generate a danger for the operator.
Do not perform measurements in environmental conditions not within the
limit values indicated in § 10.5
lways use the windproof protection when carrying out measurements in
environments where air currents are present
Do not subject the instrument to strong mechanical stress and keep the
microphone dry
1.3. AFTER USE
When measurements are completed, turn off the instrument.
If the instrument is not to be used for a long time, remove the battery.
EN - 3
HT155 - HT157
2. GENERAL DESCRIPTION
This manual refers to models HT155 and HT157. In the manual, the generic term
“instrument” refers to both devices and, if not otherwise indicated, characteristics are to be
considered as common to both models
The instrument has the following functions:
Measurement of sound pressure level (SPL) Type 1
Real-time and statistic analysis
Octave band and in 1/3 octave band analysis (HT157 only)
Measures weighted in frequency by means of A, C and Z curves and F, S impulses
Fast, Slow, Impulse, PeakC+, Peak C- integrations
Measurement of noise equivalent levels (Leq)
Inner memory for saving measures and recordings
AC analogue output for connection to external dataloggers
USB interface for connection to PC and/or USB pen drive
Wide backlit LCD display
The front panel of the instrument bears the function keys for the selection of the abovelisted functions (see chapter 4.2). The measured value appears on the wide LCD display
with the indication of the measuring unit and of the enabled functions.
In the lower part of the instrument there are the terminals for the AC analogue output with
3,5 mm coaxial connector and the (USB) ports for the connection of a possible DC 5V
external adapter for power supply without using the internal battery and RS-232 (nonactive output)
In the rear part of the instrument there is a hole for installing the instrument onto a possible
tripod while measuring.
EN - 4
HT155 - HT157
3. PREPARATION FOR USE
3.1. INITIAL INSPECTIONS
Before shipment, the instrument’s electronics and mechanics have been inspected.
All possible precautions have been taken in order for the instrument to be delivered
without damage.
However, we recommend generally inspecting the instrument in order to detect any
damage suffered during transport. Should you detect any anomalies, immediately contact
the forwarding agent.
Moreover, we recommend checking that the package contains all parts listed in § 10.6.
Should you find any discrepancy, please contact the dealer.
Should it become necessary to return the instrument, please follow the instructions
reported in § 11.
3.2. INSTRUMENT POWER SUPPLY
The instrument is supplied by 4x1.5V alkaline batteries type AA IEC LR06 included in the
package. The battery duration is of approximately 8 hours. When batteries are almost flat,
the symbol “ ” appears on the display, further to the indication “BATTERY LOW”. To
replace the batteries, follow the instructions given in § 9.2.
The instrument may be supplied also by means of the provided external DC 5V supply
connected to the USB interface. It is not necessary to remove the internal battery when
the external power supply is connected. The instrument is provided with an automatic
control which detects the presence of batteries or power supply and monitors the battery
voltage. In case the external power supply is used and supply drops while measuring, the
instrument passes directly to using the batteries, with no measurement interruption.
3.3. CALIBRATION
The instrument complies with the technical specifications reported in this manual. The
instrument performance is guaranteed for 12 months.
3.4. STORAGE
In order to guarantee precise measurements, after a long storage period, in extreme
environmental conditions, wait for the instrument to return to normal conditions (see the
environmental specifications listed in § 10.5)
EN - 5
HT155 - HT157
4. OPERATING INSTRUCTIONS
4.1. INSTRUMENT DESCRIPTION
4.1.1. FRONT PANEL
LEGEND:
1. Microphone
2. ON key
3. OFF key
4. CANCEL key
5. Key to turn on the backlight
6. LCD display
7. ENTER key
8. EXIT key
9. OUTPUT key
10. START/PAUSE key
11. Arrow key for programming
12. Arrow key for programming
13. Arrow key for programming
14. Arrow key for programming
15. SETUP key for programming
Fig. 1: Description of the instrument’s front panel
4.1.2. OUTPUT INTERFACE
Fig. 2: Description of the output interface
EN - 6
LEGEND:
1. AC analogue output
2. RS-232 interface (not active)
3. Mini USB interface
HT155 - HT157
A
4.2. DESCRIPTION OF FUNCTION KEYS
Key Description
Pressing the ON key allows turning on and internally resetting
the instrument at any time
The OFF key allows turning off the instrument
The CANCEL key allows deleting the saved data from the
instrument’s memory
ctivates/deactivates the display’s backlight. Backlight turns off
automatically after 15s
The ENTER key allows entering the internal programming
screens and confirming the selections made
The OUTPUT key allows stopping the measurements and
automatically saving the result in the memory
The START/PAUSE key allows activating or pausing a
measurement
The arrow keys allow navigating the programming menu,
increasing/decreasing the parameter values by one unit (press
, , ,
and hold the keys for fast advance) and adjusting the display
contrast
The SETUP key allows rapidly accessing the programming
menu without passing from the main menu when a
measurement is in progress
4.3. ANALOGUE OUTPUT DESCRIPTION
The instrument is provided with an AC voltage analogue output proportional to the input
signal measured in dB, which can be used to connect a 3.5mm output jack with the
characteristics shown in Fig. 3
Fig. 3: Description of jack for AC analogue output
The proportion between the output and the input signal depends on the measuring range
of the instrument and is shown in the following table:
Gain range Output/input ratio Measuring range [dB]
-10dB 0.316 50~140
0dB 1 40~130
10dB 3.16 30~120
20dB 10 20~110
30dB 31.6 10~100
40dB 100 0~90
The impedance of the AC output signal is 1k. We recommend that the charge resistance
connected to the AC output is at least 100k and that the charge capacity is lower than
200pF. The ratio between the input and the output signal is 1mV / 0.1dB. The max output
voltage is 3.2V.
EN - 7
HT155 - HT157
4.4. DISPLAY CONTRAST ADJUSTMENT
The instrument allows adjusting the display contract, proceeding as follows:
1. Turn on the instrument by pressing the key. The display shows the following
screen:
Fig. 4: Display contrast adjustment
2. Within 5s, press the arrow keys “ ” and “ ” respectively to decrease or increase the
contrast level of the display. This parameter is shown in the upper right-hand part of the
box “Realtime Analyzer”. Up to 30 contrast levels are possible
4.5. TURNING ON/OFF THE INSTRUMENT
Respect the following instructions when turning on and off the instrument
Press the key to turn on the instrument. The main screen in which the possible
measuring modes are listed is shown on the display. Use the keys “ ” and “ ” for
selecting and confirm with “ ”. If no key is pressed within 5s, the instrument
automatically sets itself to the last mode used
Pressing the
instrument back to the initial selection menu
Press the key to turn off the instrument. With the instrument turned off, the
instrument’s clock does not stop working thanks to the internal back-up battery. This
battery is continuously recharged when the instrument is measuring and at least 24
hours are necessary for a complete charge. With fully charged back-up battery, the
internal clock is maintained for over 3 months
The measurement results are saved in an internal flash memory and are always
maintained even with no external power supply or with the instrument turned off
key when measuring automatically resets the system and brings the
EN - 8
HT155 - HT157
4.6. CONFIGURATION OF MEASURING PARAMETERS
4.6.1. FOREWORD
Before activating a recording operation, it is necessary to set the necessary parameters
such as the measure name, the measuring time, etc., on the instrument, starting from
section “Setup” of the main menu (see Fig. 5) or pressing the “ ” key inside a measuring
section. The instrument will automatically save the values of the parameters each time it is
turned off, subsequently recalling them each time it is turned on.
CAUTION
It is not possible to access the “Setup” section while the instrument is
recording
Fig. 5: Selection of the instrument’s SETUP section
4.6.2. PROGRAMMING MENU INTERFACE
Select the “Setup” section in the main menu and confirm with “ ”. The instrument
displays the screen shown in Fig. 6:
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Fig. 6: Internal screen of programming menu
The single items can be selected by using the “ ” and “ ” keys and pressing the “ ” key
to modify the parameter values.
The following table contains the descriptions of the single lines contained in the
programming menu
EN - 9
HT155 - HT157
On the left side of the line there is the voltage battery and on the right
Line 1
Line 2
Line 3
side the back-up battery voltage. In case the voltage value is > 10V, the
message “Over” will appear on the display
In this line, it is possible to select the name of measurement as a
reference for the data saved during the operation, choosing among a list
of names, which can be created by the user (see § 4.6.3), using the “ ”
and “ ” keys. The indication “@ 1” for example is the indication of the
first name available in the list
In this line it is possible to define, by using the “ ” and “ ” keys, a
criterion for the choice of the measure name. In particular, two modes are
available:
Auto mode the measure name is automatically changed by the
instrument each time a new measurement is started
Manual mode the measure name is not changed automatically by
the instrument and only the user can make the change
By using the “ ” and “ ” keys, it is possible to select the options:
Line 4
Line 5
Line 6
Line 7
Option No the instrument directly starts measuring when the “ ”
key is pressed
Option Yes before starting measuring, the instrument accesses the
Setup section when the “ ” key is pressed, so that the parameters
can be checked and/or changed. When the “ ” key is pressed, the
instrument starts measuring. This option is not available for the
“24Hours” operating mode
In this line it is possible to select, by means of the “
delay time (max 10s) for the activation of measurement after the “ ”
key is pressed. Value “0” indicates no delay. This option is not
available for the “24Hours” operating mode
In this line, by means of the “ ” and “ ” keys, it is possible to activate
(On) or deactivate (Off) the print of the values shown on the display by
means of a mini-printer connected to the RS-232 output, by pressing the
“ ” key. This function is not available
In this line it is possible to set the total measuring time, from 1s to 24
hours. The instrument allows rapidly setting, by means of the “ ” and
“ ” keys, the following 12 preset levels: 10s, 1min, 5min, 10min, 15min,
20min, 30min, 1h, 2h, 4h, 8h, 24h, or it is possible to set the desired
value by using the “ ” and “ ” keys to move to the “h”, “m” or “s” fields
and the “
” and “ ” keys to set the values
” and “ ” keys, a
Line 8 This line contains the date of the instrument’s Fw version
EN - 10
HT155 - HT157
4.6.3. DEFINING THE MEASURE NAME
By selecting Line 3 inside the programming menu (see Fig. 6) and pressing the “ ” key,
the instrument displays the following screen, which shows a list of the measure names
created by the user:
Fig. 7: Screen containing the list of measure names
The first column, “Num”, refers to the number of the memory location used for saving the
measure name. The second column, “Name”, indicates the saved name, associated to the
relevant location
The instrument is capable of saving up to 256 measure names. If this
CAUTION
reference is exceeded, it automatically deletes all 256 names already
created, only saving the last input name
To create a new measure name, proceed as follows:
1. Select Line 2 inside the programming menu (see Fig. 6) and press the “
” key. The
instrument displays the following screen:
Fig. 8: Initial screen for setting the measure name
EN - 11
HT155 - HT157
2. Press “ ” again to enter the next screen, where it is possible to digit the measure
name by using the “ ”, “ ”, “ ” and “ ” keys, for the selection of the available
characters, and the “ ” key to cancel the last input character.
Fig. 9: Screen for typing the measure name
3. Press the “ ” key to confirm each character of the measure name (m ax 14 characters
available)
4. Press the “ ” key to save the created measure name, which will be automatically
present in Line 2 of the programming menu, further to the number of the location
assigned to it.
5. Press the “ ” key to exit the programming menu
CAUTION
For a more rapid creation of the measure names, we recommend using the
provided software and to subsequently send these elements to the instrument
connected to the PC via USB interface. Deletion of the measure names on
the instrument is only possible via the software (see § 8.4.4)
EN - 12
HT155 - HT157
5. CARRYING OUT MEASUREMENTS
The instrument is capable of carrying out different types of analyses of the sound pressure
level of a noise source:
1. Statistic analysis of noise
2. Spectrum analysis of noise with octave-band filter (1/1) (HT157 only)
3. Spectrum analysis of noise with third-octave band filter (1/3) (HT157 only)
For simplicity, the following descriptions are referred to the instrument model HT157
5.1. STATISTIC ANALYSIS OF NOISE
5.1.1. INITIAL OPERATIONS
1. Turn on the instrument by pressing the “ ” key. The screen for the selection of the
analysis type is shown on the display for approximately 5s (see Fig. 10)
Fig. 10: Initial screens of statistic analysis
2. Use the keys “ ” and “ ” the option “Stat.Analyzer (00101)” and confirm with “ ”.
The instrument shows the main menu of the statistic analysis, consisting of 6 icons on
the display
3. Select the relevant icon and press “ ” to enter the specific menu. In detail:
Statistic the instrument measures the sound pressure level with weighting “A”,
with time constant Fast and equivalent noise level
24 Hours measurement of the sound pressure level in a fixed time period of 24
hours
Integral the instrument integrates the sound pressure level in the three frequency
weightings (A, C, Z) and in the three time constants (Slow, Fast, Impulse)
Data Section which contains the data of the recordings saved with the instrument
(see chapter 7)
Setup allows accessing the instrument’s programming menu (see § 4.6)
Calibrate section in which it is possible to calibrate the sensitivity level of the
microphone by using the provided portable calibrator HT151 (see § 6.1.3)
4. The indication next to the icon “ :XXX” in the right-hand top part of the display
indicates the number of the group of the datum which can be saved in the instrument’s
memory
EN - 13
HT155 - HT157
5.1.2. STATISTIC ANALYSIS OPERATIONS
1. Select the “Statistic” icon and confirm with “ ”. The ins trument shows the following
screen relevant to the numerical display of the measured quantities
Line 1
Lines 2,8
Line 9
Fig. 11: Numerical screen of statistic analysis
The left part shows the current date/time set on the instrument, while the
right part shows the measuring range currently used by the instrument.
Both the parameters can be programmed by the user as follows:
Date/time setting
1. Use the “ ” and “ ” keys to move the flashing cursor to fields YYYY
(year), MM (month), DD (day), HH (hours), MM (minutes) SS
(seconds)
2. Use the “ ” and “ ” keys to select the desired program:
Line 1
Configuration of the measuring range
1. Use the “ ” and “ ” keys to move the flashing cursor to symbol “R”
2. Use the “
” and “ ” keys to select the measuring range among the
following options: 0 90dB, 10 100dB, 20 110dB, 30 120dB, 40
130dB, 50 140dB according to the reading carried out by the
instrument. After each range modification, the reading takes
approximately 3s to become stable
Lines 2 8
The central part of the display shows:
The measure name in the first 14 characters of the second line,
defined in the programming section (see § 4.6.3). Press the “ ” key to
change the measure name
The values of the measured quantities are updated in real time
every second. The following parameters, relevant to the sound
pressure level, are considered: LAFp, LAeq1s, LAeq,T, LAE, LAFeqT,
SD, LAFmax, LAF5, LAF10, LAF50, LAF90, LAF95, LAFmin
EN - 14
HT155 - HT157
This line contains:
The “ ” icon, which indicates the battery charge level
The “ ” icon, which indicates the measuring mode. In the same
position, the following messages can be displayed: “OVER” and
“UNDER”, to indicate that the measured values are respectively higher
Line 9
and lower than the maximum and minimum range set. Operate on
Line 1 to change the measuring range value
The “ ” icon allows selecting the current numerical display or the
graphic display of data
The messages “Ready” (instrument ready for recording) “Run”
(instrument recording), “Pause” (instrument paused), “Save”
(instrument saving) or “End” (end of measuring campaign
2. Press the “ ” key to start recording the values of the statistic analysis with a duration
equal to the total measuring time (Tm) defined in the programming menu (see § 4.6).
The instrument displays the following screen:
Fig. 12: Statistic analysis activation
3. The “Run” message appears in the lower part of the instrument, to indicate that a
recording is currently in progress. In this condition, the indication of the measuring
range disappears and the measuring time appears, and cannot be changed while
recording
4. By pressing the “ ” key while recording, the instrument is paused. The indication
“Pause” appears in the lower part of the instrument. Press the key a second time to
start recording again
5. When pressing the “ ” key with paused instrument, measurement is stopped and the
result is saved in the internal memory
6. When pressing the “ ” key with paused instrument, the measurement being carried
out is cancelled and the instrument waits for a new recording
7. With the flashing cursor on the “ ” icon, press the “ ” or “ ” keys to access the
graphic display of the measure. The instrument displays the following screen:
EN - 15
HT155 - HT157
Fig. 13: Graphic screen of statistic analysis
8. The screen shows the diagram of the statistic distribution corresponding to the
recording in progress, with update every second. The left part of the graphic displays
the statistic percentage of the sound pressure level corresponding to the dB value
measured by the instrument, which can be changed by means of the “ ” and “ ”
arrow keys, within the measuring range reported on the x-axis. In the example in Fig.
13, the value of the sound pressure level is 61dB in 9.9% of the values measured
within the 40 – 139dB range.
9. Press the “ ” key to pass from the statistic distribution diagram to the cumulative
distribution diagram (Accumulation), which shows each statistic level of the noise
10. In the graphical screens, it is always possible to pause and/or stop recording in the
same way as with numerical display, which it is always possible to go back to by
pressing the “ ” or “ ” keys, with the cursor on the “Graph” icon
CAUTION
The main menu cannot be selected while recording. Cancel or stop recording
to carry out this operation
11. Once the measuring time has elapsed, the recording stops and the result is
automatically saved in the instrument’s memory. The “End” message appears in the
lower part of the instrument
EN - 16
HT155 - HT157
5.1.3. 24-HOUR ANALYSIS OPERATIONS
The “24Hours” analysis is a statistic analysis, but has a fixed duration of 24 hours starting
from the programmable date/time, and divides the measuring results of the various
quantities in 24 intervals of one hour each. After the analysis has automatically stopped,
the calculated values of Ld, Ln and Ldn noise are also provided. This mode is appropriate
when it is necessary to repeat an analysis of a certain duration (measuring time) from the
same second of each hour during a whole day.
CAUTION
The measuring time within each interval can be set (see § 4.6.2) in a range of
1min 59min. For a measuring time different from this range, the instrument
automatically considers a time of 20min
1. Use the keys “ ” or “ ” to select the “24Hours” icon (see Fig. 14) and confirm with
”.
“
Fig. 14: Selection of 24Hours analysis
2. The instrument shows the following screen relevant to the measured quantities in
numerical form:
Line 1
Line 2
Lines 3-8
Line 9
Fig. 15: 24Hours analysis screen in numerical form
3. Consider the following table for the meaning of the items found in screen of Fig. 15:
EN - 17
HT155 - HT157
The left part shows the current date/time set on the instrument, while the
right part shows the measuring range currently used by the instrument.
Both the parameters can be programmed by the user as follows:
Date/time setting
1. Use the “ ” and “ ” keys to move the flashing cursor to fields YYYY
(year), MM (month), DD (day), HH (hours), MM (minutes) SS
(seconds)
2. Use the “ ” and “ ” keys to select the desired program:
Line 1
Line 2
Lines 3- 8
Configuration of the measuring range
1. Use the “ ” and “ ” keys to move the flashing cursor to symbol “R”
2. Use the “ ” and “ ” keys to select the measuring range among the
following options: 0 90dB, 10 100dB, 20 110dB, 30 120dB, 40
130dB, 50 140dB according to the reading carried out by the
instrument. After each range modification, the reading takes
approximately 3s to become stable
By using the “ ” or “ ” keys to move the flashing cursor to the
“hh:mm” field and repeatedly using the “ ” or “ ” keys, the
instrument shows the 24 intervals from “0:00 to 23:00” and the values
of the Ld, Ln, Ldn parameters. By moving the cursor to the symbol “”
and pressing the “ ” or “ ” keys, the instrument shows the
following quantities in a horizontal line: LAeqT, Lmax, Lmin, L5, L10,
L50, L90, L95, SD, LAFeq, corresponding to the statistic analysis of
the sound pressure level with frequency weighting “A” and time
constant F
These lines show in real time the values of the quantities integrated by
the instrument during the whole measuring time and the resulting values
at the end of each interval
The left part of the line shows:
The “ ” icon, which indicates the battery charge level
The “
The “
(with flashing cursor on the icon, press the “
Line 9
4. With the message “Ready” on the display, press the “ ” key to enter the instrument’s
programming menu and set the relevant parameters (measure name, measuring time,
etc…) as described in § 4.6). Press the “ ” key to go back to the measuring screen
to graphic display “Graph”)
The messages “Ready”, “Run”, “Wait” or “End”, to respectively
indicate: waiting to start measuring, measurement in progress, waiting
to start measuring in new range and end of measurement
The indication in real time (e.g.: 49.0 dB) of the sound pressure level
measured by the instrument
” icon, which indicates the current operating mode.
” icon, to indicate the type of numerical display of the results
” or “ ” keys to pass
EN - 18
HT155 - HT157
5. Press the “ ” key to start measuring. After this operation, the instrument:
Starts measuring from the minute indicated in the system date/time and shows this
reference in column “hh:mm” with the relevant values of the quantities read in real
time
Shows the message “Run” on the display
In line 1, it shows the measuring time “Tm” instead of the indication of the set range
Disables the possibility of accessing the programming menu by pressing the “ ” key.
Stops measuring to enter the programming menu again
6. Once the measuring time has elapsed, the instrument:
Shows the indication “Wait” on the display, to indicate that it is waiting to start
(instant “00”) in the new measuring interval at the hour following the initial one (see
) (e.g.: if measurement is started at 8:49, the second measurement will be started at
9:49:00)
Shows the measuring range again instead of the measuring time “Tm”
This operation is repeated for each of the remaining 24 intervals
Fig. 16: Screen of instrument waiting to start a new recording (Wait)
CAUTION
When a measurement is in progress (Run) or waiting (Wait), the
”,“ ”,“ ”,“ ”,“ ” keys are not active and it is necessary to stop or
“
cancel measurement to activate them again
7. With the flashing cursor on the “ ” icon, press the “ ” or “ ” keys to access the
graphic display of the measure. The instrument displays the following screen:
Initial line
Central lines
Final line
Fig. 17: Screen of graphic display in 24Hours mode
EN - 19
Loading...