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CEL-450

Casella CEL-490, CEL-450 Operator's Handbook Manual

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November 2005
CEL-450 & CEL-490
REAL-TIME
SOUND LEVEL METERS
Operators Handbook
HB3307-04
Warnings !
LOAD BATTERIES following the instructions given in Section 1.3. Make sure they are inserted in the orientations shown inside the battery compartment .
A single cell installed with the wrong polarity may still allow the instrument to function, but will cause overheating severe enough to rupture a cell, with consequent risk to the operator and damage to the instrument.
DO NOT REMOVE the protective grid from Class 1 microphone capsules as this will expose the diaphragm, which is extremely vulnerable to damage.
UNDER NO CIRCUMSTANCES should these instruments be cleaned using a solvent based cleaner.
Repairs of damage caused by a failure to observe these warnings will NOT be covered by the normal warranty conditions.
Notes !
The CEL-450 and CEL-490 are supplied complete with Class 1 or Class 2 Electret Microphones and have no need of a 200V polarizing supply. Therefore no such supply is available and it is safe to ignore the 200V polarising supply warnings shown on CEL-250 or MK 250 microphone packaging.
Throughout this book, display screens that are available only on a CEL-490 will be shown with a dashed ----outline.
CEL-450/490 Operators Handbook - Page 3
Contents
Contents
Chapter ................... Page
1. INTRODUCTION . . . . . . . . . . . . . . . . . . 7
1.1 Display & Keys .................... 7
1.2 Quick Edit ....................... 9
1.3 Install Microphone, Preamplifier & Batteries .... 10
1.4 Switch Instrument ON/OFF ............. 10
1.5 Description ..................... 12
1.6 CEL-450 Sound Level Meter ............ 14
1.7 CEL-490 Sound Level Meter ............ 15
1.8 Instrument Power Supplies ............. 16
1.9 dB23 SoundTrack Software ............. 17
2. PRELIMINARY OPERATIONS . . . . . . . . . . . . 19
2.1 Select Instrument Configuration (Language,
Microphone Response Etc.) ............. 19
3. SELECT MEASUREMENT MODE,
TIMER SETTINGS & SETUP . . . . . . . . . . . . 23
3.1 Select Measurement Mode
(Bandwidth) ..................... 23
3.2 Select Run Timing .................. 23
3.3 Select Measurement Setup
(Factory- or User-Prepared Setups) ......... 27
3.3.1 Select Broadband Measurement Setup ....... 27
3.3.2 Select Narrow Band Measurement Setup ..... 32
4. ACOUSTIC CALIBRTION CHECK . . . . . . . . . . 37
4.1 Perform Acoustic Calibration Check ........ 37
4.1.1 Automatic Calibration Check ............ 38
4.1.2 Manual Calibration Check .............. 41
5. OPERATION . . . . . . . . . . . . . . . . . . . . 45
5.1 Measurement .................... 45
5.1.1 Start Measurement ................. 45
5.1.2 Broadband Measurement .............. 46
5.1.3 Narrow Band Measurement ............ 49
5.2 Recall Stored Data ................. 54
CEL-450/490 Operators Handbook - Page 5
Contents
1. INTRODUCTION
Please read Sections 1.1 to 1.4 before commencing measurement. For a quick introduction to instrument operations, Chapter 4 may be used as a tutorial.
1.1 Display & Keys
AFmx
dB
AF
Aeq
AFmn Zpk
LL
L
L
L
0 140
v04001
Stop /Run /Pause indicator
(Instrument is in Run mode)
Period number
Battery condition
Principal parameter Principal level Run-Time elapsed
Bandwidth
Icons showing active keys
Analog display of SPL
and levels
Additional parameters
Switches instrument On/Off Changes menu (=operating mode
)
Enables Quick Edit function Operates display back light Move cursor (=select options) Stops a measurement Accesses stored data Starts/Pauses/Restarts a
Measurement run
ШШШШШШ
73.8dB
65.4dB 69.9dB
69.4dB
Ø:1Ø
Figure 1: Display & Key Identities
(Further icons may be shown during operation)
Introduction
CEL-450/490 Operators Handbook - Page 7
The broadband screen in Figure 1 shows one principal and four subordinate parameters, where the principal parameter is a level as identified below.
The following frequency weightings may be shown:
A-, C- and Z- (Linear) weighted.
The following time weightings and other identities may be shown.
S Slow. F Fast.
I Impulse.
pk Peak. mx Maximum. mn Minimum. eq Equivalent continuous level. AV Average level. Tm3 Taktmaximal 3 sek. Tm5 Taktmaximal 5 sek. EP,v L
eq
based noise dose normalised to a user specified period of hours and minutes. When the period is specified as 8 hours, this measurement unit will be shown as EP,d.
TWAv Time Weighted Average is the normalised time
averaged sound pressure level with the selected frequency and time weighting that represents the total average of a persons workplace noise exposure averaged over a user specified period of hours and minutes. This unit of measurement is specified in the USA: OSHA standard 1910-95 published in 1983. When the period is specified as 8 hours, this measurement unit will be shown as TWA.
N Percentile sound level. AE Sound exposure level. HML Calculated as L
Ceq-LAeq
L
evel
AS
L
98001
8
Frequency Weighting
Time Weighting
Introduction
Page 8 - CEL-450/490 Operators Handbook
1.2 Quick Edit
All control functions for the CEL-450 and CEL-490 are accessed via menu displays. In addition a powerful Quick Edit facility can be invoked by
the key to allow measurement parameters and settings to be changed quickly and easily on screen. Figure 2 shows how the quick edit function enables the cursor keys to edit the current settings.
73.8dB
ШШШШШШ
Ø:1Ø
Cpk
Cpk
dB
dB
dB
dB
AS
AS
A
CF
ASmx
CFmn
CFmn
CFmx
CFmx
Ceq
Ceq
L
L
L
L
72.1dB 68.6dB
L
L
L
L
L
L
L
L
64.8dB
Press
Change
Setting
Highlight Parameter To Select It
Other Parameters Will Have Changed
All Parameter Levels Are Shown In Run Mode
Press
Press
Stop
Quick Edit
Stop
Run
v04002
0 140
0 140
0 140
0 140
Figure 2: Quick edit functions
Introduction
CEL-450/490 Operators Handbook - Page 9
1.3 Install Microphone, Preamplifier & Batteries
Screw the Class 1 microphone “finger tight” on to the preamplifier. With the instrument switched OFF, insert the connector of the preamplifier plus Class 1 microphone or Class 2 microphone / preamplifier unit into the socket in the cone at the top of the instrument case. Face the red dot on the preamplifier to the front of the instrument so that the key engages in a keyway in the socket to ensure correct pin connection.
(To disconnect the preamplifier unit from the instrument, pull on the knurled sleeve.)
Load four new 1.5 V batteries (AA or equivalent) into the battery compart­ment in the rear of the instrument (Figure 3).
Make sure they are inserted in the orientations shown inside the compartment.
One cell installed with wrong polarity may still allow the instrument to function, but can cause overheating severe enough to rupture a cell and damage the instrument.
1.4 Switch Instrument ON/OFF
1. Press to switch the instrument ON.
The instrument starts a series of self tests, during which it indicates the instrument type, firmware version, preamplifier type and interface status.
Serial Number Label
Tripod Bush (1/4" Whit.)
980016
Figure 3: Battery orientation
Introduction
Page 10 - CEL-450/490 Operators Handbook
At the end of the self test sequence, the instrument displays
memory information and battery voltage,
followed by the identity of the last used setup.
Finally it enters calibration check mode (described in Chapter 2).
512Kb
13Jan04 1Ø:54:42
1% 2 Format
Memory Full Runs
1-02
Current date and time
Last used setup
Setup
Press MENU
User Setup 1
Key to Start
1-03
1-04
dB
Auto 114.ØdB
L
ZF
Ø9JanØ4 11:28
80 - 190028A - NN Preamp
CEL49ØA.1 vNN.NN
I/O ID:
Class 1 None NNNNNN
1-01
Inst. Type 450/490 Inst. Version A = Broadband
B = Octave band C = Third octaves 1 = Class 1 2 = Class 2
Firmware version
Program version and issue
Interface status Inst. identification number
The dates and times of the last 4 calibrations are stored.
See Section 2.2.
Introduction
CEL-450/490 Operators Handbook - Page 11
2. Press to switch the instrument OFF when all measurement, setup and data recall operations are finished.
1.5 Description
Both the CEL-450 and CEL-490 Sound Level Meters make use of recent developments in digital processors to feature a full 0 - 140 dB dynamic range on a single uninterrupted scale. In addition, the narrow band versions of these instruments offer real time frequency analysis.
Versions of these instruments are available with Class 1 or
Class 2 measurement accuracy to give an ability to make comprehensive sound level measurements.
The main
difference between the CEL-450 and CEL-490 is the additional timing facilities included in the CEL-490. The CEL-450 is intended primarily to make the noise measurements required for Industrial Hygiene and Health & Safety standards, while the more comprehensive timing features of the CEL-490 make it more suited to the monitoring of Environmental noise.
Versions of both instruments are available for broadband
measurement, broadband plus octave band, and broadband, octave band and third-octave band measurement. All frequency bands operate in real time, using Class 0 filters.
To simplify
operation, frequently used measurement setups can be stored for re-use. The setup memory can accommodate one factory setup and up to four user specified setups for each bandwidth.
Class 1 and Class 2 Measurement. Broadband, Octave Band and Third Octave
Band versions. Simultaneous measurement of up to 16
parameters in broadband mode. Simultaneous measurement of up to 10
parameters in narrow band mode. Quick Edit function for immediate parameter
change. One factory setup and up to four user
specified setups stored for each bandwidth. Up to four profiles can be attached to each
measurement.
CEL-450 CEL-490 Cumulative Measurement x x Profile Measurement x x Period Measurement x Duration Timers x x Delay Timers x Ln% Measurement x
Introduction
Page 12 - CEL-450/490 Operators Handbook
Simple procedures allow a measurement setup to be selected and the instrument to make the required measurements and save them automatically in separate data memories for each bandwidth.
Data stored in the memory can be recalled to the display for inspection, so that the operator can confirm that the results are valid before leaving the test site.
The instruments can be operated and deliver adequate results without the need for other equipment, beyond an acoustic calibrator. All operations can be controlled via the instrument keypad and simple menu options. Figure 4 shows the basic arrangement of the main menu, while a more comprehensive menu structure is given on the fold out sheet at the back of this book.
However, the instruments become even more versatile when their measurement and setup data is downloaded to a PC using the dB23 Windows™ based software. This software has the facilities expected of fully featured Windows™ packages offering post processing, cut and paste between applications, comprehensive word processing capabilities, and extensive on screen graphing facilities.
Figure 4: Simplified menu structure
(Some of these options may not be available on all versions)
Measure
Mode
Setup
Calibration
Main Menu
Memory
Configure
Status
Set
Bandwidth
Select
Setup
Auto/Man Line input
View/
Delete
Timers
v04009
PC Communications Language Backlight Graph Range Time & Date Microphone Response AC Out
p
ut
Date & Time Memory Use
SLM Parameters Measurement Period Functions Dose Parameters Profiles
Set
Parameters
Calibrate
Select
Directory
Select
Data
Run Timer Delay Timer
Introduction
CEL-450/490 Operators Handbook - Page 13
These instruments are constructed to withstand some of the toughest industrial conditions with cases formed from a polyester/ polycarbonate material, giving them a high resistance to damage. Data integrity is further protected by the use of robust electret microphones.
1.6 CEL-450 Sound Level Meter
The CEL-450 is ideal for on-site noise surveys and can also monitor personal noise exposure in accordance with European - ISO or USA ­OSHA and DOD standards. The following weightings can be set:
RMS: A, C, Z (see section 1.1) weightings,
Peak: A, C, Z weightings,
Time: F (fast), S (slow),
I (impulse),
Q: 3, 4, 5, 6 energy conversion factor. Broadband models can measure all of the following parameters simul­taneously with a single time constant.
L
AF
Sound level, with current weightings (A and F are shown),
L
AFmx
Maximum level, with current weightings,
L
AFmn
Minimum level, with current weightings,
L
Aeq
Equivalent continuous level, with current frequency weighting, Together with L
Ceq
is used for HML calculations
of heaing damage,
L
AIeq
Equivalent continuous level, with impulse weighting,
L
Zpk
Linear peak,
L
AE
Sound exposure level (sometimes known as SEL),
L
Ep,v
Noise dose normalised to a user selected (variable) period of hours and minutes, When the period is set to 8 hours, this will be shown as L
ex,8h
.
L
Tm3
Cumulative average of fast weighted maximum values taken over 3s periods (Taktmaximal 3),
L
Tm5
Cumulative average of fast weighted maximum values taken over 5s periods (Taktmaximal 5),
TWA
v
Time Weighted Average is the normalised time averaged sound pressure level with the selected frequency and time weighting that represents
Introduction
Page 14 - CEL-450/490 Operators Handbook
the total L
Avg
of a person’s workplace noise exposure averaged over a user selected (variable) period of hours and minutes. This unit is specified in the USA: OSHA standard 1910-95 published in 1983. When the period is set to 8 hours, the unit will be shown as TWA.
L
Avg
Average level over the measurement period.
HML This value is the calculation: L
Ceq-LAeq
.
Profiles Up to 4 parameters can be selected to have their
profile stored. Period times between 10 ms and 30 minutes can be selected.
Narrow band models can measure and scan the following parameters simultaneously.
L
AF
Sound level, with current weightings (A and F are shown here),
L
AFmx
Maximum level, with current weightings
L
AFmn
Minimum level, with current weightings
L
Aeq
Equivalent continuous level, with current frequency weighting.
L
pk
User selectable measured broadband L
Zpk,LCpk
or L
Apk
presented as a single result.
Cumulative measurements are saved for each user enabled parameter. In addition, broadband mode allows up to four profiles to be stored for each result set, with intervals from 10ms to 30min. L
N
% statistical data
can be measured and stored.
All sound level measurement parameters can be set from the keypad and the whole measurement range is shown on a single 0 - 140 dB scale. The instruments have 2 Mb of memory, which is used on a first-come basis. Duration timers can also be set in the main menu, allowing the instrument to automatically switch off after a pre-defined time.
1.7 CEL-490 Sound Level Meter
The CEL-490 is recommended for detailed measurements as, in addition to the CEL-450 capabilities described above, it has more comprehensive
Introduction
CEL-450/490 Operators Handbook - Page 15
run timing facilities. These allow it to operate with user set delayed start and stop times, and to store period results taken at regular intervals.
1.8 Instrument Power Supplies
All of these instruments are powered by a set of four standard AA size batteries in a compartment in the back of the instrument case, and it is recommended that alkaline IEC Type LR6 be used. Rechargeable batteries can also be employed, but some types may give a shorter operating life. Zinc carbon batteries are NOT recommended.
If there is doubt whether the batteries will be able to power the instrument for the start and stop times set, or when measurements are needed over long periods, the instrument can be powered directly from an external 12V DC supply without the need to remove the internal batteries.
DAMAGE to the instrument will occur if an
external power supply exceeds 14V DC. The
nominal external supply is 12V DC.
External power for the instrument is supplied via a 2.1 mm co-axial 2-line D.C. connector in the bottom of the instrument case. Terminal polarity is +12V DC on the tip and 0V DC ground on the sleeve.
A Casella CEL Universal Power Supply (-PC18) may be used to power the instruments from nominal 110-240V 50/60 Hz mains supplies. To prevent loss of data should an external power supply be interrupted for any reason during measurement, it is recommended that a usable set of batteries be kept in the instrument.
In general, download all important data and remove the batteries from the instruments when they are to be out of use for some time.
Note that when an instrument is returned to battery operation after being powered from an external supply, either: switch the instrument OFF then ON again, or: disconnect ALL devices from the DC input socket, in order to avoid additional discharging of the internal batteries.
The instrument contains a built in lithium battery to maintain stored data and setups for periods while the instrument is switched OFF.
Introduction
Page 16 - CEL-450/490 Operators Handbook
1.9 dB23 SoundTrack Software
The CEL-6813 dB23 Software enables data collected by the CEL-450 and CEL-490 to be downloaded to a PC for storage, manipulation and the production of reports. It also enables the PC to exercise comprehensive control over the sound level meter.
Data can be exported in ASCII format to proprietary word processing software, while profile and statistical data can be exported as tab-delimited text files suitable for use with spreadsheets such as Lotus 123™ (Release 2 or later) and MS Excel™. In addition, on-screen graphing and reporting facilities are available and full on-line control can be exercised over the sound level meter.
The dB23 Software runs under MS Windows
®
taking advantage of the control facilities offered by the environment, so that once installed, users with a modest knowledge of Windows will find many operations are performed almost instinctively with a minimum of learning time.
Downloading is performed under the control of the PC. Data from each of the measurement runs in the sound level meter is transferred as a series of associated datafiles together with a note file in which comments and information can be written. Once downloaded, the user can display the following information:
¤ Run summary for each run,
¤ Data file,
¤ Up to four profiles for each run,
¤ Notepad for user-entered notes.
Introduction
CEL-450/490 Operators Handbook - Page 17
Hints For Using Menus
1. and displayed on a menu show which option keys are active.
2. In general, and keys move the reverse video cursor from field to field.
3. In general, and keys change the entry in the cursor field.
4. at the bottom of a menu list indicates there may be further options.
5. An indication such as 3/5 at the bottom of a menu
1
shows that option 3 has been
selected from the 5 available.
6. Settings left highlighted on a menu screen become the active options.
Note 1: The illustrations in this book are for full featured
instruments, other instruments may offer fewer or no options.
Introduction
Page 18 - CEL-450/490 Operators Handbook
2. PRELIMINARY OPERATIONS
2.1 Select Instrument Configuration (Language, Microphone Response Etc.)
Select the language in which the instrument will present menu options. This should be the first operation so that the displays and options will be understood.
Similarly, to get the most accurate results, these instruments
must be operated with a known microphone directional response and be calibrated for this response.
When the language and microphone response are known to be
correct for the proposed measurement task, go directly to Section 4.1 Calibration Check.
European IEC standards require measurements to be performed
with microphones that have a Free Field response, while the U.S.A. ANSI standards require Random Incidence microphones. The micro­phone response is set via the Configuration menu.
Normally, these more permanent characteristics must be set
only once, as the instrument will store the settings and use them the next time it is switched on.
Proceed as follows.
Operation Press Display Shows Comments
1. Switch the instrument ON
Start up messages are displayed that include: Instrument Type, Firmware Version, Etc. Finally, the Configuration screen is displayed with Battery Voltage, followed by the Calibration check screen.
2. Select the Main menu
2 times
This is the Main menu. It gives access to further menus that select: Measurement Mode, Measurement Setup, Calibration Sequence, Timers Data Recall from Memory, Instrument Configuration, Status.
2-01
dB
L
ZF
Auto 114.Ø
Ø9JanØ4 11:28
Calibration Timers
1/7
2-02
Setup
Measure Mode
Measure Mode
CEL-450/490 Operators Handbook - Page 19
Preliminary Operations
Operation Press Display Shows Comments
3. Select the Configure option
or
Move the reverse video cursor to the required line.
4. Move to the Configure menu
This menu allows the following items to be set: RS232 Communication Baud rates from 1200 to 115200, Menu Language, Backlighting Durations of 1, 5, 10, 15, 30 s, OFF or Manual press ON press OFF, Graph span and offset, Instrument Time & Date, Microphone Response Free Field or Random, A.C. Output for line transmission or recording.
5. Select the Language option
or
Move the reverse video cursor to the required line.
6. Move to the Language menu
This menu allows the following languages to be selected for menu presentation: English, Français, Deutsch, Italiano, Español.
7. Select the required language
or
The highlighted language will be used for menu presentation. This setting will also be stored and used next time the instrument is switched on.
Press to return to the Configuration menu.
Calibration Memory
2-03
Setup
Configure
5/7
Language Backlight
2-04
RS232 Comms
Graph Range
1/7
Backlight
2-05
RS232 Comms
Time & Date
Language
2/7
Deutsch
2-06
English
Italiano
Français
1/5
Deutsch
2-07
English
Italiano
Français
2/5
Page 20 - CEL-450/490 Operators Handbook
Preliminary Operations
Operation Press Display Shows Comments
8. Select the required microphone response (and other configuration items) in the same way.
Date and time are set using the quick edit function as follows.
The highlighted entries will be used. These settings will also be stored and used next time the instrument is switched on.
9. Select the date and time option by moving the reverse video cursor to the required line on the Configure menu.
10. Move to Date and Time menu
This menu allows the time and date to be set.
11. When the date and time are to be changed
This enables the quick edit function.
Use and to select a
field, and and to change the entry. The day will be determined automatically from the date and month entries.
Press again to save the date and time.
12. Return to the Main menu
2 times
All of the configuration settings that have been left highlighted on the menu screens, plus any changes to the time and date, will be stored for use next time the instrument is switched on.
Ø9:51:27
Mon 2ØØ4
Jan
2-08
1/2
12
Ø9:51:27
Mon 2ØØ4
Jan
2-09
1/2
12
CEL-450/490 Operators Handbook - Page 21
Preliminary Operations
Page 22 - CEL-450/490 Operators Handbook
Preliminary Operations
3. SELECT MEASUREMENT MODE, TIMER SETTINGS, & SETUP
3.1 Select Measurement Mode (Bandwidth)
The measurement mode specifies the bandwidth that is to be used for measurement. Select the measurement mode as follows.
Operation Press Display Shows Comments
1. Start from the Main menu
This is the Main menu screen.
2. Select the Measure Mode option
and
Move the reverse video cursor to the required line.
3. Move to the Measure Mode menu
This menu allows any of the available bandwidths to be selected. The highlighted setting will be used. This setting will also be stored and used the next time the instrument is switched on.
When the required bandwidth has been selected, press once to obtain a Measurement screen or twice to obtain the Main menu that gives access to all settings and stored data.
3.2 Select Run Timing
Measurements can be timed as follows.
Timers Off Manually timed. This allows the user to start and
stop a measurement run whenever they want.
Calibration Timers
3-01
Measure Mode
Setup
2/7
Calibration Timers
3-02
Measure Mode
Setup
1/7
Third Octave
3-03
Broadband
Octave
2/3
CEL-450/490 Operators Handbook - Page 23
Select Mode & Setup
Duration Run for a predetermined duration after pressing
the run key. This can be used to time a work shift, or to measure some particularly noisy operation with a known work cycle.
Sync timer (CEL-490 only) Run for a predetermined duration
that is synchronized to start at the same time as the next measurement period which was set via the Setup menu. For example, if the Period Time is 30 minutes, the run will start when the time is exactly on the hour or 30 minutes past the hour. This method is suggested when precisely timed measurements are required.
Delay Timer (CEL-490 only) Run with preset start and stop
times. This allows the instrument to start and stop up to seven accurately timed measurement runs while unattended. In this way, different measuring times can be set for each day of the week with the option of repeating them over a period of several weeks. Each time is set as Day:Hour:Minute, so that delays can be set up to a month ahead.
Set the Day to 00, to use this as a 24 hour timer. Once set, the timer settings become valid for all bandwidths and setups. Display screens that are available only for a CEL-490 are shown with a dashed ----line.
When timed measurements are required, proceed as follows.
Operation Press Display Shows Comments
1. Start from the Main menu
This is the Main menu screen.
Calibration Timers
3-01
Measure Mode
Setup
2/7
Page 24 - CEL-450/490 Operators Handbook
Select Mode & Setup
Operation Press Display Shows Comments
2. Select the Timers option
and
Move the reverse video cursor to the required line.
3. Move to the Timers menu
The Timers menu allows the following run timer functions to be set: Timers ON/OFF, Run Duration Timer, with or without Synchronization to the measurement periods, Delay Timer (CEL-490 only)
Use up to seven sets of Run Start and Stop times that may be repeated up to 999 times.
4. If required select Duration Timer from Timers menu
followed
by
These options control the run duration. The Synchronization Timer may be used together with the Duration Timer. When the Duration setting is used alone, the run starts
immediately is pressed and continues for the duration set.
Run Durations of ---­(=none set), 1, 5, 10, 15, 20, 30 minutes, 1, 2, 4, 8, 12, 24 hours may be set.
When the Synchronization
Timer is used (√) together
with the Duration setting, the run starts at exactly the same time as the first measurement period
starting after is pressed and continues for the duration set.
Calibration
Timers
3-04
Measure Mode Setup
1/7
3-05
Duration Timer Delay Timer
Timers Off
1/3
3-06
Sync Timer X
Sync Timer
Duration - - - -
1/2
CEL-450/490 Operators Handbook - Page 25
Select Mode & Setup
Operation Press Display Shows Comments
5. If required, set Duration and Sync Timer
to enable quick edit mode.
Use and to select a field.
Use and to change the entry in the field. Save the settings by
pressing again to resume normal operation.
Press to return to the Timers menu.
6. When a CEL-490 is being used, if required select Delay Timer from the Timers menu
followed
by
The first menu allows the seven sets of run start and stop times to be repeated up to 999 times.
When required, use to enable quick edit mode, use
and to change the
entry, then save the setting
by pressing again.
7. Select second Delay Timer menu
The second menu controls seven sets of run start and stop times where the time is shown as Day/Hour:Minute. Different measuring times can be set for each day of the week with the option of repeating them over a period of several weeks. When a Delay Timer is used
(√), the run starts at the
preset start time and stops at the preset stop time.
8. If required, set the Delay Timer
to enable quick edit mode
Use and to select a field.
Use and to change the entry in the field from X
to √.
Save the settings by
pressing again to resume normal operation.
Press to return to the Timers menu.
3-07
Sync Timer X Duration ----
1/2
3-08
Repeat 4
Repeat
3-09
T1 X T2 X T2 X
T1 X ØØ/ØØ:ØØ
ØØ/ØØ:ØØ ØØ/ØØ:ØØ ØØ/ØØ:ØØ
1/14
3-10
T1 X T2 X T2 X
T1 X ØØ/ØØ:ØØ
ØØ/ØØ:ØØ ØØ/ØØ:ØØ ØØ/ØØ:ØØ
1/14
Page 26 - CEL-450/490 Operators Handbook
Select Mode & Setup
When the required timer settings have been selected, press once to obtain a Measurement screen or twice to obtain the Main menu that gives access to all settings and stored data.
3.3 Select Measurement Setup (Factory- or User-Prepared Setups)
The Setup specifies the particular parameters to be measured. Selection procedures for broadband and narrow band measurements are similar, although a wider choice of parameters is available for broadband, while the range of frequency bands displayed can be restriced for narrow band.
One factory configured setup and up to four user defined setups
can be stored for each available bandwidth.
Measurements can be made at specified time intervals with
storage of period noise data and exceedance (L
n
) values and profiles. Display screens that are available only for a CEL-490 are shown with a dashed ----line.
3.3.1 Select Broadband Measurement Setup
The factory setup for broadband measurement contains a set of standard parameters selected for general purpose use.
User setups contain parameters selected to perform some particular task and are saved under a user setup identity. Changes to user setups are saved for re-use, however any changes to the factory setup will be lost and the standard settings offered each time the instrument is re-started.
Select and save broadband setups as follows.
Operation Press Display Shows Comments
1. Select Broadband Measure­ment as detailed in Section 3.1
When the Broadband option is highlighted, it will be the bandwidth used.
Third Octave
3-11
Broadband
Octave
1/3
CEL-450/490 Operators Handbook - Page 27
Select Mode & Setup
Operation Press Display Shows Comments
2. Display the Main menu, and select Setup
then
or
This is the Main menu screen with the reverse video cursor highlighting the Setup option.
3. Move to the Setup selection menu
This menu allows any of the available setups for broadband to be selected. Highlight the setup that is to be used. This setup will also be stored and used the next time the instrument is switched on.
4. Move to the Setup Screen
This screen allows the following parameters to be selected: SLM weightings, Period measurement on/off, Measurement Functions, Dose parameters.
5. If required select SLM Response from the Setup screen
or
then
This screen allows the following weightings to be set: RMS: A, C, Z, Time: F, S, I, Peak: A, C, Z, Q: 3, 4, 5, 6.
6. If required, change the weightings
to enable quick edit mode
Use and to select a field.
Use and to change the entry in the field. Save the settings by
pressing again to resume normal operation.
Press to return to the Setup screen.
Calibration Timers
3-12
Measure Mode
Setup
2/7
User Setup 2 User Setup 3
3-13
Factory Setup
User Setup 1
2/5
Functions Dose Results
3-14
SLM Response
Periodic
1/4
3-15
Time Weight F Peak Weight Z Exchange Q 3
RMS Weight A
1/4
3-16
Time Weight F Peak Weight Z Exchange Q 3
RMS Weight A
1/4
Page 28 - CEL-450/490 Operators Handbook
Select Mode & Setup
Operation Press Display Shows Comments
7. Select Functions from the Setup screen to enable Cumulative parameters to be set
or
then
This screen allows selection of cumulative (CUM) measurement where the function’s value will be accumulated both over the whole run, and over regular periods. The screen also allows selection of Profile measurement where the values will be recorded at regular intervals to give a profile of the run.
The Profile interval can be set to: 10, 20, 50, 100, 250, 500, milliseconds, 1, 5, 10, 15, 20, 30 seconds, 1, 5, 10, 15, 20, 30 minutes.
When both Period and Profile times are switched off, the instrument will skip this screen and go directly to the selection of cumulative functions, Step 8.
8. Select measure­ment functions from the Cumulative screen
This screen allows the following measurement functions to be specified
(√ =enabled, X =disabled)
using the weightings set in step 6 above:
L
AF LTm5
L
AFmx
H
ML
L
AFmn
L
AF10.0
LAeq
L
AF50.0
L
Zpk
L
AF90.0
L
AE
L
AF95.0
L
EP,8h
L
AF99.0
L
Tm3
LAFLarge
Histogram.
L
AF
Large allows the principal parameter shown in large characters on the display to be changed to any of the selected functions.
Any L
AF
% value between
0.1 and 99.9 can be set.
Cum
1/2
Period Profile
3-17
-----
3-18
AFmn
Aeq
CUM
LLL L
Zpk
LL
AFmx
LL
1/16
CEL-450/490 Operators Handbook - Page 29
Select Mode & Setup
Operation Press Display Shows Comments
9. If required,
enable (√)
or disable (X) the functions
to enable quick edit mode
Use and to select a field.
Use and to change the entry in the field. Save the settings by
pressing again to resume normal operation.
Then press to return to the Setup screen.
10. Select Period from the Setup screen to enable measure­ment intervals to be set
or
then
This screen allows a period to be specified for regular sequential measurement and a shorter interval to be set for the storage of profiles. Period measurement is available only with a CEL-490.
The predicted maximum run time with the currently selected parameters and periods and the available unused memory are also indicated. Period measurement is possible only with a CEL-490.
The broadband measure­ment period can be set to: 1, 5, 10, 15, 20, 30 seconds, 1, 5, 10 ,15, 20 , 30 minutes, 1 hour, ----(=none).
When available, the profile interval must be equal to or shorter than the period setting. The profile interval can be set to: 10, 20, 50, 100, 250, 500, milliseconds, 1, 5, 10, 15, 20, 30 seconds, 1, 5 10, 15, 20, 30 minutes. Profiles for any of the enabled parameters can be stored.
Press to access quick edit to specify measurement and profile periods.
3-19
AFmn
Aeq
LLL L
Zpk
LL
AFmx
LL
1/16
CUM
3-17
Profile ----­Max Run Time 45 Days 11:26:ØØ
Period 1min
1/4
Page 30 - CEL-450/490 Operators Handbook
Select Mode & Setup
Operation Press Display Shows Comments
11. Select Period and Profile Functions from the Period Setup screen
The Period and Profile functions are set in the same way as the cumulative
functions (√ =enabled, X
=disabled) and use the weightings set in step 6 above.
Period and profile measurement have the following restrictions: Histogram and H
ML
functions are not available,
L
AF LTm5
L
AFmx
L
AFmn
L
AF10.0
LAeq
L
AF50.0
L
Zpk
L
AF90.0
L
AE
L
AF95.0
L
EP,8h
L
AF99.0
L
Tm3
A maximum of 4 profiles can be attached, The period or profile time must be 1 minute before LN% values are available.
12. If required,
enable (√)
or disable (X) the functions
to enable quick edit mode
Use and to select a field.
Use and to change the entry in the field. Save the settings by
pressing again to resume normal operation.
Press to return to the Setup screen.
13. Select Dose Results from the Setup screen to enable dose measure­ment
or
then
This screen allows the dose threshold and normalisation period to be set. Only levels above the threshold level will be included in the dose measurement.
The threshold can be set to 0, or in 1 dB steps between 70and90dB. U.K legislation requires that the threshold be set to 0.
3-21
AFmn
Aeq
PER
LLL L
Zpk
LL
AFmx
LL
1/16
3-22
AFmn
Aeq
LLL L
Zpk
LL
AFmx
LL
1/16
PER
3-23
7Ø
8 Hours
EP,d
L
WA
T&
Threshold
1/2
CEL-450/490 Operators Handbook - Page 31
Select Mode & Setup
Operation Press Display Shows Comments
The dose normalisation period is the duration to which the actual dose measurements are “normalised” to give comparable L
EP,8h
and
TWA
V
results from measure­ments with different durations. Any normalisation period between 1 minute and 24 hours 59 minutes can be set.
14. If required, change the dose settings
to enable quick edit mode
Use and to select a field.
Use and to change the entry in the field. Save the settings by
pressing again to resume normal operation.
Press to return to the Setup screen.
When the required broadband setup has been selected, press once to obtain the Broadband Measurement screen or twice to obtain the Main menu that gives access to all settings and stored data.
3.3.2 Select Narrow Band Measurement Setup
The factory setup for narrow band measurement contains a standard set of parameters selected for general purpose use. Octave and third octave setups have the same parameter selections and are selected in a similar way.
User setups contain parameters that have been selected to perform some particular task and are saved under a user setup identity. Changes to user setups are saved for re-use. However any changes to the factory setup will be lost and the standard settings offered each time the instrument is re-started.
Select and save narrow band setups as follows.
8 Hours
EP,d
L
WA
T&
Threshold
7Ø
3-24
1/2
Page 32 - CEL-450/490 Operators Handbook
Select Mode & Setup
Operation Press Display Shows Comments
1. Select Octave or Third Octave Measure­ment as detailed in Section 3.1
The highlighted option will be the bandwidth used.
2. Display the Main menu, then select Setup
then
or
This is the Main menu screen with the reverse video cursor highlighting the Setup option.
3. Move to the Setup selection menu
This menu allows any of the available setups for the chosen narrowdband to be selected. Highlight the setup that is to be used. This setup will also be stored and used the next time the instrument is switched on.
4. Move to the Setup Screen
This screen allows the following parameters to be selected: SLM weightings, Period measurement on/off, Measurement Functions, Frequency range.
5. If required, change the weightings
to enable quick edit mode
Use and to select a field.
Use and to change the entry in the field. Save the settings by
pressing again to resume normal operation.
Press to return to the Setup screen.
Third Octave
3-30
Broadband
Octave
2/3
Calibration Memory
3-31
Measure Mode
Setup
2/7
User Setup 3
3-32
Factory Setup User Setup 1
User Setup 2
3/5
Functions Freq. (Hz)
3-33
SLM Response
Periodic
1/4
3-34
Time Weight F Peak Weight Z Exchange Q 3
RMS Weight A
1/4
CEL-450/490 Operators Handbook - Page 33
Select Mode & Setup
Operation Press Display Shows Comments
6. Select Functions from the Setup screen to allow measure­ment parameters to be set
or
then
This screen allows selection of cumulative (CUM) measurement where the function’s value will be accumulated both over the whole run, and over regular cumulative periods.
This screen enables functions to be selected for measurement and enables an interval (Period) to be set over which the function will be measured.
The period interval can be set to: 1, 5, 10, 15, 20, 30 seconds, 1, 5, 10, 15, 20, 30minutes, 1 hour, ----(=none).
Press to access quick edit to specify cumulative periods.
7. Select measure­ment functions from the Cumulative screen
This screen allows the following measurement functions to be specified
(√ =enabled, X =disabled)
using the weightings set in step 5 above:
L
AFmx
L
AF50.0
L
AFmn
L
AF90.0
L
Aeq
L
AF95.0
L
Zpk
L
AF99.0
L
AF10.0
Histogram.
Note that L
AF
is not available
as a cumulative function.
8. If required,
enable (√)
or disable (X) the functions
to enable quick edit mode
Use and to select a field.
Use and to change the entry in the field. Save the settings by
pressing again to resume normal operation.
Cum
1/2
Period
s-30
-----
3-37
AFmn
Aeq
LLL L
Zpk
LL
AFmx
LL
1/10
CUM
AFmn
Aeq
LLL L
Zpk
LL
AFmx
LL
1/10
3-38
CUM
Page 34 - CEL-450/490 Operators Handbook
Select Mode & Setup
Operation Press Display Shows Comments
9. Select Period from the Setup screen to enable measure­ment intervals to be set
or
then
This screen allows a period to be specified for regular sequential measurement. Period measurement is available only with a CEL-490.
The predicted maximum run time with the currently selected parameters and periods and the available unused memory are also indicated.
The narrowband measure­ment period can be set to: 10, 20, 50, 100, 250, 500 milliseconds, 1, 5, 10, 15, 20, 30 seconds, 1, 5, 10 ,15, 20 , 30 minutes, 1 hour, ----(=none).
Press to access quick edit to specify measurement and periods.
10. Select Period Functions from the Period Setup screen
This screen allows the following measurement functions to be specified
(√ =enabled, X =disabled)
using the weightings set in step 5 above:
L
AF
L
AF50.0
.
L
AFmx
L
AF90.0
L
AFmn
L
AF95.0
L
Aeq
L
AF99.0
L
AF10.0
.
Note that L
Zpk
is not available as a period function.
11. If required,
enable (√)
or disable (X) the functions
to enable quick edit mode
Use and to select a field.
Use and to change the entry in the field. Save the settings by
pressing again to resume normal operation.
3-35
Max Run Time 5 Days 11:26:ØØ
Period 1min
1/3
AFmx
AFmn
LLL L
Aeq
LL
AF
LL
1/9
3-39
PER
AFmx
AFmn
LLL L
Aeq
LL
AF
LL
1/9
3-40
PER
CEL-450/490 Operators Handbook - Page 35
Select Mode & Setup
Operation Press Display Shows Comments
12. Select Frequency from the Setup screen to change the range of frequency bands measured
or
then
This screen allows the range of frequency bands measured to be restricted to a particular range of interest.
13. If required, change the range of frequency bands measured
to enable quick edit mode
Use and to select a field.
Use and to change the entry in the field. Save the settings by
pressing again to resume normal operation.
Press to return to the Setup screen.
When the required narrow band setup has been selected, press once to obtain the Narrow Band Measurement screen or twice to obtain the Main menu that gives access to all settings and stored data.
3-41
ZCA 12Hz - 20kHz
Third Octave
Bands
3-42
ZCA 12Hz - 20kHz
Third Octave
Bands
Page 36 - CEL-450/490 Operators Handbook
Select Mode & Setup
4. ACOUSTIC CALIBRATION CHECK
4.1 Start Acoustic Calibration Check
It is recommended that a calibration check of the microphone be made both before and after a measurement run. A record of the last calibration before the run and the first calibration after the run are stored. This gives the confidence that the microphone remained calibrated throughout the measurement period.
In addition to storing a “before” and “after” calibration with every measurement, the instrument saves the last four calibrations, which can be viewed on the instrument screen.
At the end of a calibration check, the user is offered the option of saving the new calibration, or not saving it and reverting to the previous calibration.
If any runs have been completed since the the previous calibration, ensure that only a calibration with the correct level is saved, as this calibration will be saved as the first calibration after a run and once stored it cannot be changed. Saving a new calibration will also calibrate the “next” measurement. However, the user always has the option of performing another calibration immediately before any future run is started.
The calibration level indicated by the instrument will depend on the microphone response set. Therefore, an acoustic calibration check should be performed only when the microphone response is correct for the required task. When the calibration is known to be acceptable, press
once to obtain a Measurement screen or twice to obtain the Main
menu that gives access to all settings and stored data.
It is recommended that an acoustic calibration check be performed both BEFORE and AFTER a measurement run.
Perform the calibration check using a CEL-110/1 (or 284/2) Class 1 Calibrator for sound level meters with Class 1 accuracy (WS2) and a CEL-110/2 (or CEL-282) Class 2 Calibrator for Class 2 instruments (WS3). All of these calibrators provide a nominal level of 114.0 dB at 1 kHz, while the CEL-110/1 can also supply a calibration level of 94 dB. However, the exact value to which the instrument must be calibrated will depend on the microphone type in use, its response and the local atmospheric conditions.
CEL-450/490 Operators Handbook - Page 37
Acoustic Calibration Check
v04010
1
M
Operation Press Display Shows Comments
1. Start with the Auto calibration screen
This is the Automatic calibration check screen. It shows the current sound level.
2. Inspect other stored calibration levels
The last four calibration levels are stored.
Press to return.
3. Switch the Calibrator ON
This shows the level determined by the sound level meter.
The calibration levels required for CEL Class 1 and Class 2 microphones and for Free Field and Random Response are shown in Table 1.
4. When the correct calibration level should be
114.0 dB
Start an automatic calibration to the level shown at Auto. (In this example 114.0 dB.)
A CALIBRATING message will be displayed, then after a few moments either FAILED, or CALIBRATED.
The Automatic calibration can fail if the input signal is outside the calibration adjustment range (approx. ±6 dB).
Refer to Step 6 to change the Auto calibration level.
4-01
dB
Auto 114.ØdB
L
ZF
Ø9JanØ4 11:28
4-02
Ø3JanØ4 14:23 114.ØdB Ø3JanØ4 16:35 113.8dB Ø5JanØ4 Ø9:17 114.ØdB Ø5JanØ4 13:45 114.ØdB
4-03
dB
Auto 114.ØdB
L
ZF
Ø9JanØ4 11:28
4-04
dB
Auto 114.ØdB
L
ZF
CALIBRATING
CEL-450/490 Operators Handbook - Page 39
Acoustic Calibration Check
4-05
4-06
Operation Press Display Shows Comments
7. Edit the Automatic calibration level
Press or to change the level over the range 85.0 to 130.0 dB in 0.1 dB steps.
Press again to save the new level.
8. Perform a new Automatic calibration
or
Highlight L
ZF
again.
Then as described in Step 4,
press to perform an automatic calibration to the new level.
4.3 Manual Calibration Check of the Microphone
Normally, Auto calibration will be used as the most convenient method. However, the user has the option of performing a manual microphone calibration, for example when the calibration source is outside the limits of the automatic calibration (85.0 to 130.0 dB).
Operation Press Display Shows Comments
1. Start with the Auto calibration screen
This is the Calibration Check screen. It shows the current sound level.
2. Highlight Auto
or
This allows manual operation to be selected.
4-07
dB
Auto 113.8dB
L
ZF
Ø9JanØ4 11:28
4-08
dB
Auto 113.8dB
L
ZF
Ø9JanØ4 11:28
4-08
dB
Auto 113.8dB
L
ZF
Ø9JanØ4 11:28
dB
L
ZF
Auto 114.ØdB
Auto
4-09
Ø9JanØ4 11:28
CEL-450/490 Operators Handbook - Page 41
Acoustic Calibration Check
4-10
4-11
4-12
4-13
4-14
Operation Press Display Shows Comments
8. When the level is correct
To allow the new setting to be saved as the current calibration
4
.
9. Save the calibration
or
The user is given the option of saving or not saving the new calibration.
Press again to use the highlighted option and save the calibration.
Or use or to highlight NO SAVE to ignore the current calibration and use the previous calibration.
When the calibration check is complete, press once to obtain a Measurement screen or twice to obtain the Main menu that gives access to all settings and stored data.
L
ZF
Ø9Jan04 12.22
dB
4-15
Manual
4-16
dB
Manual
L
ZF
NO SAVE YES
Note 4: The instrument saves the four most recent calibrations.
CEL-450/490 Operators Handbook - Page 43
Acoustic Calibration Check
5. OPERATION
5.1 Measurement
With the instrument configured, the calibration checked, timers set and measurement parameters specified as described in the preceding chapters, measurements can be performed as described below.
This chapter may also be used as a tutorial to give an idea of how the instrument functions by accepting the currently selected measurement parameters and the last saved calibration.
5.1.1 Start Measurement
Operation Press Display Shows Comments
1. Switch the instrument ON
Start up messages are displayed that include: Instrument Type, Firmware Version, Etc., Finally, Calibration check mode is displayed showing current sound level and details of the last calibration.
2. If required perform a Calibration Check as described in Chapter 4, or go directly to step 3
3. Move to Measure­ment, i.e. accept the Last Calibration
A Stop screen will be shown, where indicates
stop mode and the instrument operates with the last used measurement setup (or the setup just selected as described in Chapter 3).
4. When the Measure­ment screen looks like this
The last setup used was broadband.
When broadband measurement is required, follow the instructions given in Section 5.1.2.
When narrow band measurement with B and C models is required, change the bandwidth to narrowband as described in Section 3.1, then proceed to Section 5.1.3.
5-01
dB
Auto 114.ØdB
L
ZF
Ø9JanØ4 11:28
AFmx
dB
AF
Aeq
AFmn Zpk
LL
L
L
L
5-02
0 140
CEL-450/490 Operators Handbook - Page 45
Operation
Operation Press Display Shows Comments
5. When the Measure­ment screen looks like this
The last setup used was narrow band. When narrow band measurement with B and C models is required, follow the instructions given in Section 5.1.3. When broadband measurement is required, change the bandwidth to broadband as described in Section 3.1, then proceed from Section 5.1.2.
5.1.2 Broadband Measurement
Operation Press Display Shows Comments
1. Start from the Broadband Measure­ment screen
Continue broadband measurement.
2. Start a measure­ment run (i.e. store data)
shows a run is now in
progress.
When periods are disabled, the time since the start of the current run is shown at the top right.
When periods are enabled, the number of completed periods is shown at the top left of the screen and the time since the start of the current period at the top right.
3. If a screen like this is displayed while a CEL-490 is being used
The delay timer has been enabled. The clock icon shows that this is a Wait screen with current date and time, plus the time at which the run will start.
Once the run has started, go to Step 5.
Z
I
Z93.6
L
dB
16k
4k
1k
2506316
40
80
120
ACZ
5-03
dB
AFmx
dB
AF
Aeq
AFmn Zpk
LL
L
L
L
5-02
0 140
Ø:1Ø
72.7dB
ШШШШШШ
AFmx
dB
AF
Aeq
AFmn Zpk
LL
63.2dB 9Ø.1dB
L
L
L
67.4dB
5-04
0 140
Wed 14 Jan 2ØØ4
Ø9:45:21
12:ØØ:ØØ
5-05
Page 46 - CEL-450/490 Operators Handbook
Operation
Operation Press Display Shows Comments
Setting the Delay timer is described in Section 3.2.
(If required, press to abort the run and return to step 2.)
4. Inspect stored data
A data header screen for the current run will be displayed.
It indicates the time elapsed since the start of the current run (duration), bandwidth, preamplifier type, and setup in use.
5. Inspect further data from the current run
The levels accumulating during the run for the first eight parameters of the setup in use are displayed together with the time elapsed so far for the run (or period).
These levels may be seen to change as more data is collected.
When using a CEL-490, once the first period has
been completed, press to inspect period data from the run.
and are displayed only when more than one period has been stored.
6. Once the first profile interval has been completed
Inspect broadband profile data from the run.
On this screen, the time axis autoranges depending on profile interval
Use and to scroll through time.
Press again to view the other profiled functions.
ØØ:Ø9:21
Type 1
5-06
Dur. Preamp.
Factory Setup 1
67.4dB
72.7dB
Aeq
AFmx
Tm3
AE
Zpk
AFmn
Tm5
EP,d
L
L
L
L
9Ø.1dB
63.2dB
65.ØdB
- - -.-dB
L
L
LL63.8dB
67.7dB
5-07
ØØ:ØØ:Ø1:26CUM
dB
5-08
11:13:31:Ø973459
Aeq
L
40
80
120
0 1sec 2sec
CEL-450/490 Operators Handbook - Page 47
Operation
Operation Press Display Shows Comments
Press to add a cursor readout.
Now use and to move the cursor and
and to change the
dB scaling.
Press again to return to normal operation.
7. When all required data samples have been inspected
Leave data inspection and return to the Run screen.
8. If some sound occurs that must be excluded from broadband measure­ment
indicates that data collection is paused (for example while someone speaks to the operator), however timing continues without interruption.
can be used to pause measurement only from a Run screen.
9. When the sound to be excluded has stopped
Data collection is resumed and the run icon displayed.
can be used to resume a paused measurement only from a Pause screen.
10. When sufficient data has been collected
can be used to end measurement only from a Run screen.
The current run is stopped and three options are offered.
1:45
72.7dB
AFmx
dB
AF
Aeq
AFmn Zpk
LL
63.2dB 9Ø.1dB
L
L
L
67.4dB
5-09
0 140
ØØØØ18
2:56
72.7dB
AFmx
dB
AF
Aeq
AFmn Zpk
LL
63.2dB 9Ø.1dB
L
L
L
67.4dB
5-10
0 140
ØØØØ28
72.7dB
AFmx
dB
AF
Aeq
AFmn Zpk
LL
63.2dB 9Ø.1dB
L
L
L
67.4dB
5-11
0 140
ØØØØ31 Ø2:31
Continue Run
Stop Run
Stop Run
Restart Run
5-12
Page 48 - CEL-450/490 Operators Handbook
Operation
Operation Press Display Shows Comments
Stop Run: End run and store data (go to Step 1). Restart Run: Abort current run and start a new one (return to Step 9). Continue Run: Ignore “Stop” and continue with current run (return to Step 8).
Use and to select an option, then confirm it by
pressing .
11. Confirm end of run
The current run is ended and all data from the run stored.
indicates that the run
has stopped.
5.1.3 Narrow Band Measurement
Operation Press Display Shows Comments
1. Start from the Narrow Band Measure­ment screen
Continue narrow band measurement. This screen shows real-time levels measured simu­ltaneously in all bands against a single 140 dB scale, or a user selected scale.
The preset broadband value is always shown in reverse video. The level and frequency of the band marked by the line cursor are identified.
Use and to scan the bands.
Use and to access other parameters selected for the current measurement.
AFmx
dB
AF
Aeq
AFmn Zpk
LL
L
L
L
5-13
0 140
C
I
77.3
L
dB
16k
4k
1k
2506316
40
80
120
AZ
5-20
dB
125Hz
C
CEL-450/490 Operators Handbook - Page 49
Operation
Operation Press Display Shows Comments
2. If required, change the measure­ment functions
to enable quick edit mode
The measurement functions can be selected as follows. All broad and narrow bands: F, S or
I time weighting with
A, C or Z frequency weighting, so that pre-weighted frequency analysis can be performed.
Use and to select a field.
Use and to change the entry in the field. Then save the settings by
pressing to resume normal operation.
3. If required, change the display span and offset, and the range of scanned frequencies
This activates quick edit.
4. Select the top end of the dB scale
or
This allows the top end of the displayed scale to be changed, i.e. the span.
Use and to make the required changes.
5. Select the bottom end of the dB scale
or
This allows the bottom end of the displayed scale to be changed, i.e. the offset.
Use and to make the required changes.
16k
4k
1k
2506316
40
80
120
AC
L
5-21
dB
AF 77.3125Hz
Z
Z
Ø:17ШШШШШШ
16k
4k
1k
2506316
40
80
120
AC
93.3
5-22
dB
Z
I
L
0-140dB
Z
Z
0- dB140
Ø:17ШШШШШШ
16k
4k
1k
2506316
40
80
120
AC
93.3
5-23
dB
Z
I
L
Z
Z
0 -140dB
0
Ø:17ШШШШШШ
16k
4k
1k
2506316
40
80
120
AC
93.3
5-24
dB
Z
I
L
Z
Page 50 - CEL-450/490 Operators Handbook
Operation
Operation Press Display Shows Comments
6. Return to the measure­ment screen
7. Start a measure­ment run (i.e. store data)
shows that a run is in
progress.
Press quick edit and use
and to move the frequency cursor when in quick edit mode.
It is possible to change the span and offset of the display scale when a narrowband measurement screen is displayed. This allows points of particular interest to be magnified.
Use to change the range between 40 and 140 dB. Then once the range has
been changed, use to change the offset.
8. If a screen like this is displayed while a CEL-490 is being used
The delay timer has been enabled. The clock icon shows that this is a Wait screen with current date and time, plus the time at which the run will start. Once the run has started, go to Step 9. Setting the Delay timer is described in Section 3.2.
(If required, press to abort the run and return to step 1.)
9. Inspect data stored during the current narrowband run
A data header screen for the current run will be displayed.
It indicates the time elapsed since the start of the run (duration), bandwidth, preamplifier type, range and setup in use.
Z
Ø:17ШШШШШШ
16k
4k
1k
2506316
40
80
120
AC
93.3
5-25
dB
Z
I
L
Z
Ø:17ШШШШШШ
16k
4k
1k
2506316
40
80
120
AC
5-26
dB
Z
I
L
77.3125Hz
Z
Wed 14 Jan 2ØØ4
Ø9:45:21
12:ØØ:ØØ
5-27
CEL-450/490 Operators Handbook - Page 51
Operation
Operation Press Display Shows Comments
10. Inspect further stored data
This screen shows the cumulative spectrum saved for the first measurement parameter (in this example L
ZImx
).
and may be used to inspect other data screens saved for the run, for example cumulative data from other functions and period data.
11. Inspect further stored data
This screen shows a period spectrum saved for the first measurement parameter (in this example L
ZImx
).
and may be used to inspect other data screens saved for the run.
12. Enable inspection of individual frequency bands
The individual bands may now be scanned by means
of and .
The selected band is indicated by a line cursor.
13. Inspect individual frequency bands
and
The band centre frequency is shown at the top centre of the screen, with the level in the band to the right.
14. When all required data samples have been inspected
Leave data inspection and return to the relevant measurement screen.
Z
Ø:37ØØØ13Ø
16k
4k
1k
2506316
40
80
120
AC
98.3
5-30
dB
ZImx
L
Z
Ø:37
16k
4k
1k
2506316
40
80
120
AC
98.1
5-31
dB
Z
Imx
L
Z
ØØØ13Ø
Z
Ø:37
16k
4k
1k
2506316
40
80
120
AC
78.1
5-32
dB
Z
Imx
L
125Hz
ØØØ13Ø
Z
Z
27:17
16k
4k
1k
2506316
40
80
120
AC
93.3
5-33
dB
Z
I
L
ØØØ255
Z
Page 52 - CEL-450/490 Operators Handbook
Operation
Operation Press Display Shows Comments
15. If some sound occurs that must be excluded from the frequency measure­ment
indicates that data collection is paused (for example while someone speaks to the operator), however timing continues without interruption.
can be used to pause measurement only from a Run screen.
16. When the sound to be excluded has stopped
Data collection is resumed and the run icon displayed.
can be used to resume a paused measurement only from a Pause screen.
17. When sufficient data has been collected
can be used to end measurement only from a Run screen. The current run is stopped and three options are offered. Stop Run: End run and store data (go to Step 1 for another measurement). Restart Run: Abort current run and start a new one (return to Step 3). Continue Run: Ignore “Stop” and continue with current run (return to Step 9).
Use and to select an option, then confirm it by
pressing .
18. Confirm end of run
The current run is ended and all data from the run stored.
indicates that the run
has stopped.
Z
8:17
16k
4k
1k
2506316
40
80
120
AC
1Ø4.2
dB
Z
I
L
5-34
ØØØ265
Z
Z
16k
4k
1k
2506316
40
80
120
ACZ
93.5
dB
ZI
L
5-35
ØØØ265 1Ø:16
Continue Run
Stop Run
Stop Run
Restart Run
5-36
Z
I
Z92.3
L
dB
16k
4k
1k
2506316
40
80
120
AC
5-37
dB
Z
CEL-450/490 Operators Handbook - Page 53
Operation
5.2 Recall Stored Data
Data stored in the instrument can be recalled to the display for inspection. This allows the operator to check the quality of results before leaving the test site.
To display data from any stored run, proceed as follows.
Operation Press Display Shows Comments
1. Start from the Main menu
This is the Main menu. It gives access to further menus that select: Measurement Mode, Measurement Setup, Calibration Sequence, Data Recall from Memory, Instrument Configuration.
2. Select the Memory option
or
Move the reverse video cursor to the required line.
3. Move to the Memory menu
On this menu, “current” refers to the “current bandwidth”.
Bandwidth is selected via the Measure Mode option as described in Section 3.1.
4. Move to the list of run Dates for the specified bandwidth and select the required date
then
or
This menu shows the dates on which all runs with the specified bandwidth were saved (i.e. a specified bandwith or all available bandwidths).
Calibration Timers
5-40
Measure Mode
Measure Mode
Setup
1/7
Timers
5-41
Setup Calibration
Memory
5/7
5-43
Tue
Thu
Wed 7 Jan2ØØ4
9 Jan2ØØ4
13 Jan2ØØ4
15 Jan2ØØ4
Fri
Page 54 - CEL-450/490 Operators Handbook
Operation
Operation Press Display Shows Comments
5. Move to the list of Runs and select a run
then
or
This is a directory of all runs stored on the specified date with the required bandwidth.
6. View the Header for the required run
indicates that overload
has occurred during the run.
To view data from a broadband run, go to Step 7.
To view data from a narrow band run, go to Step 8.
7. Inspect stored broadband data
This screen shows the first eight cumulative parameters from the selected broadband run.
Use to display the remaining cumulative parameters from the selected run.
When CEL-490 data is being inspected and period data is included in the run, press
to display screens
containing period data.
and are displayed when more than one period has been completed to show that these keys can be used to access data from other periods.
8. Inspect stored narrow band data
This screen shows a spectrum from the selected narrow band run.
Use to display other functions from the selected run.
Use to enable and
to move the cursor to
obtain the level in each band.
5-44
14:37:Ø6
Ø8:59:27
1
15 Jan2ØØ4
1
Tue
11:Ø9:55 1
Thu
12:45:Ø9
1
5-45
ØØ:ØØ:21
Type 1
Dur. Preamp. Range Ø - 14Ø Factory Setup
5-46
6Ø.4dB
74.3dB
Aeq
ASmx
Tm3
AE
Zpk
ASmn
Tm5
EP,d
L
L
L
L
94.8dB
47.9dB
65.ØdB
- - -.-dB
L
L
LL63.8dB
87.7dB
CUM
Z
Ø:26ØØØ137
16k
4k
1k
2506316
40
80
120
ACZ
93.3
5-47
dB
Z
I
L
CEL-450/490 Operators Handbook - Page 55
Operation
Operation Press Display Shows Comments
Press then use
and to scan the
band levels manually.
Press to cancel.
Press and to display frequency data from any other parameters stored.
Press and to display data from other periods stored.
5.3 Delete Stored Data
Unwanted data stored in the instrument can be deleted to make room for new data. Proceed as follows.
Operation Press Display Shows Comments
1. Start from the Main menu
This is the Main menu. It gives access to further menus that select: Measurement Mode, Measurement Setup, Calibration Sequence, Data Recall from Memory, Instrument Configuration.
2. Select the Memory option
or
Move the reverse video cursor to the required line.
3. Move to the Memory menu
On this menu, “current” refers to the “current bandwidth”.
Bandwidth is selected via the Measure Mode option as described in Section 3.1.
Calibration Memory
5-50
Measure Mode
Measure Mode
Setup
1/6
Calibration
5-51
Measure Mode Setup
Memory
4/6
5-52
Delete Current
Delete All
View Current View All
3/4
Page 56 - CEL-450/490 Operators Handbook
Operation
Operation Press Display Shows Comments
4. Move to the list of run Dates for the specified bandwidth and select the required date
then
or
This menu shows the dates on which all runs with the specified bandwidth were saved (i.e. a specified bandwith or all available bandwidths).
Use to tick dates where all runs for the day are to be removed, or go to Step 5 to delete individual runs.
5. Move to the list of Runs and select a run
then
or
This is a directory of all runs stored on the specified date with the required bandwidth.
Use to tick individual runs that are to be removed.
6. When all required runs have been marked
This screen asks for confirmation that the marked runs are to be deleted.
Use and to select Yes or No.
Confirm with . All selected records will be removed.
5.4. Format Memory
Formatting the memory (strictly re-formatting) is a global operation that deletes all stored data (runs) and all user setups from every available bandwidth.
USE THIS OPTION WITH GREAT CAUTION !
The option to format the instrument memory is displayed on the
final Self Test screen.
Proceed as follows.
5-53
Tue
Thu
Wed 7 Jan2ØØ4
9 Jan2ØØ4
13 Jan2ØØ4
15 Jan2ØØ4
Fri
1
3
5-54
%MEM
14:41:28 1
15 Jan1998
Ø9:15:Ø7 1
11:14:15 1
14:15:Ø4 1
Tue
1
3
1
3
1
3
1
3
1
3
5-55
2Delete
Runs
Sure ?
Yes No
1
3
CEL-450/490 Operators Handbook - Page 57
Operation
Operation Press Display Shows Comments
1. Start from the final Self Test screen.
This screen offers the Format option.
Perform Step 2 before the option is replaced by the Battery Voltage line and the calibration or menu screens.
2. When re-format is required
This screen asks for confirmation.
Use and to select Yes or No, then confirm
with . All stored data (runs) and all user setups from every available bandwidth are deleted.
5.5 Use With Tape and DAT Recorders (Including Calibration For Line Input)
Sound level meters can be connected to a DAT or tape recorder and function as an accurately calibrated input system. This enables the measured sound levels to be recorded for further calculation and analysis.
When recording, connect the recorder to the OUT Phono jack-
socket in the bottom of the sound level meter (Figure 6). This socket supplies an unconditioned AC signal with a maximum level of 0.5V RMS.
When replaying, insert the recorded signal via the IN Phono jack-
socket shown in Figure 6. Suitable signals from other sources may also be inserted for measurement or analysis in this way.
If an electrical calibration of the instrument using the microphone
substitution method is required, insert the calibration signal via a CEL-516 Line Input Adaptor (or the earlier CEL-216) screwed into a CEL-495 Preamplifier in place of the Class 1 microphone. These line input adaptors and preamplifiers may also be used with a Class 2 instrument.
Then perform an acoustic calibration as described in Chapter 4.
5-60
512Kb
13JanØ4 1Ø:54:42
1% 2 Format
Memory Full Runs
5-61
Delete All Runs
WARNING
and User Setups No Yes
Page 58 - CEL-450/490 Operators Handbook
Operation
4.5.1 Recording
DAT recorders have a typical dynamic range of 70 dB, while analog recorders often have less. To ensure the maximum dynamic range for recording while avoiding overload, the 60 to 70 dB range of the recorder must be arranged to accommodate only the top or bottom 60 to 70 dB portion of the 140 dB output from the sound level meter. This is achieved by selecting an AC output signal to match the level used to calibrate the sound level meter. The following guide lines are suggested.
1. Use a CEL-110/1, CEL-110/2, CEL-284/2 or CEL-282 Calibrator to perform an acoustic calibration check of the sound level meter at 114 dB or 94 dB, as described in Section 4.
2. Display the Configure screen, accessed from the Main screen as described in Section 2.1.
3. Select and display the AC Output screen.
4. Select Hi or Low to match the calibration level used in Step 1,
i.e. Use Low range with a 94 dB calibration,
Use Hi range with a 114 dB calibration.
5. Connect the input of the recorder to the instrument OUT terminal.
6. Select broadband L
ZF
measure mode on the sound level meter.
7. Switch the recorder ON and start it operating in record mode.
8. For accurately repeatable recordings, adjust the Record Level control on the recorder until the calibrator signal gives a reading of -12 dB on the tape recorder VU meter.
Now the top of the recording range on the tape (= 0 VU) will occur in the same place as overload on the sound level meter (140 dB or 98 dB depending on the calibration used).
2/2
5-62
Hi (7Ø-14ØdB)
Low (28-98dB)
Selected output range
CEL-450/490 Operators Handbook - Page 59
Operation
9. Record about 30 seconds of the calibration signal.
A calibration signal with known level is inserted via the sound level meter and recorded, so that when replayed, it gives an indication of the record/replay characteristics of the tape.
10. Switch the calibrator OFF and remove it from the microphone.
When the VU reading is estimated (which it usually must be at these levels), repeatability from one series of recordings to another may suffer. Therefore, either keep the Record Level control in the same position for ALL recordings, or perform a new calibration for EACH series of measurements.
11. Without touching the Record Level on the recorder, if required, change the measurement range of the instrument to accommodate the noise signal.
12. Make a note of the range used for measurement.
13. Proceed with recording the noise signal.
5.5.2 Replay
The following guide lines are suggested for replaying sound signals.
980037
2.1 mm Coaxial DC Power
Miniature 8-way DIN Interface Socket
Phono Jack Socket AC line Out
Phono Jack Socket AC line In
OUT IN
Figure 6: Bottom panel of the instrument
Page 60 - CEL-450/490 Operators Handbook
Operation
1. Start from the sound level meter Line Input Calibration screen.
Broadband L
ZF
measure mode will be selected automatically by
the sound level meter.
2. Connect the recorder output to the instrument IN terminal.
3. Switch the recorder to replay mode.
4. Replay the recorded calibration signal.
5. Adjust the Replay Level control on the recorder so that the sound level meter display indicates the calibration level for the microphone and response used.
6. Stop the recorder.
The system is now calibrated to replay at accurately determined levels with the calibration signal near the top of the input range, which gives the widest possible replay dynamic range.
However, the instrument measurement range may need to be adjusted so that the display scale gives a correct indication of the recorded values.
7. Press to enter quick edit mode.
8. Use and to select the measurement range that was noted for the measurement.
9. Press again to confirm the calibration and any scale change.
dB
dB
Ø9JanØ4 12.22
Scale -35
L
ZF
5-63
Date and time of last calibration
CEL-450/490 Operators Handbook - Page 61
Operation
The instrument replay scale now matches the scale used for the recording so that the levels indicated by the display will be correct.
10. Press to display the measurement screen, then replay the recorded material and perform any measurements and analysis required.
Page 62 - CEL-450/490 Operators Handbook
Operation
6. SPECIFICATION
6.1 General
Standards:
The CEL-450/490 series are self contained sound level meters
designed to comply with the following international standards.
IEC 61672-1 2002-5 (Electroacoustics - Sound Level Meters)
Group “X” instruments, performance Class 1 or 2 as relevant to
the instrument model.
IEC 60651: 1979, IEC 60804: 1985, ANSI S1.4: 1983, ANSI S1.
In addition, for Octave and Third-Octave band versions (B and C
models) the filters comply with:
EN 61260: 1996, Class 0 and ANSI S1.11, Order-3 Type 0C.
Octave Filters: 11 bands with centre frequencies from
16 Hz to 16 kHz (B and C models).
Third Octave Filters: 33 bands with centre frequencies from
12.5 Hz to 20 kHz (C models).
Narrow band filters may also be pre-weighted with A, C or Z
frequency weightings.
Measurement Ranges:
Single 0 -140 dB range: Operating range defined by the
self-generated noise of the instrument only. Linearity operating
range: 30-140dBA in Broadband.
Peak levels: A, C and Z available to 143 dB.
Dynamic range: Typically 123dB(A).
Level Detector: Digitally derived true root-mean-square (RMS)
detection, 0.1 dB display resolution.
Electric Noise Floor:
Noise floor with 18 pF dummy microphone: Typically
16.5 dBA.
CEL-450/490 Operators Handbook - Page 63
Specification
Total inherent Noise including microphone thermal
noise at 20 degrees C:Typically <18.5 dBA.
Frequency Response:
6 Hz to 30 kHz (upper and lower 3 dB frequencies)
with Digital sampling rate: 67.2 kHz.
Time Weightings:
S, F and I according to IEC 61672-1, with only one selected at a
time.
RMS Frequency Weightings:
A, C and Z satisfying IEC 61672-1 2002 Class 1.
Filter weightings are derived simultaneously via DSP.
Correction Filters:
Built in correction filters for Random Incidence microphones.
Reference Conditions:
20
o
C Air temperature,
101.325 kPa Atmospheric pressure,
65% Relative humidity,
114.0 dB Nominal reference level at 1kHz
Operating Environmental Conditions:
Temperature range (Class 1): -10 to +50
o
C,
Temperature range (Class 2): 0 to +40
o
C,
Humidity: 5 to 90% RH in the absence of condensation.
Atmospheric pressure: 65 to 108 kPa.
Storage Environmental Conditions:
Temperature range: -20 to +60
o
C,
Humidity: 0 to 90% RH in the absence of condensation.
Atmospheric pressure: 65 to 108 kPa.
Page 64 - CEL-450/490 Operators Handbook
Specification
Effect of Temperature:
Electrical accuracy of the instrument over -10 to
+50
o
C: < ±0.2 dB
Temperature coefficient of CEL-250 Microphone: 0.02
dB/
o
C.
Effect of Humidity:
Less than ±0.5 dB over the range 25 to 90% RH (non
condensing), relative to the reference conditions.
Supplied Microphone:
Class 1: CEL-250 ½" pre-polarised Free Field type for use with
CEL-495 Preamplifier,
Nominal sensitivity: 50 mV/Pa,
Capacitance: 18 pF.
Class 2: CEL-485 ¼" electret microphone incorporated into
preamplifier unit with internal temperature correction.
No cable correction is required for microphone cables up to 10 m
(33 ft) when calibration is performed with C6716 or C6717
Cables fitted.
Calibration:
Direct for Class 1 CEL-250 Microphone used with CEL-495
Preamplifier.
Direct for Class 2 CEL-485 Microphone/Preamplifier Unit.
Manual, or automatic calibration to a user specified reference
level.
The date, time and offset of the last 4 calibrations are stored.
Power Supply:
Batteries: 4 x LR6 Alkaline cells.
Battery Life: Typically 15 hours in broadband mode, 12 hours
in narrowband mode.
Batteries may be safely left in the instrument whilst operating
from an external DC supply.
CEL-450/490 Operators Handbook - Page 65
Specification
Remove the batteries when the instrument is to be out of
service for some time. A built in lithium battery will maintain
stored data and setup information while the instrument is
switched off.
External DC Via 2.1 mm Power Connector: 9 to 14V DC
at typically 150mA with 1000mA inrush current.
AC Output:
Approximately 0.5V RMS via “AC Line Out” jack socket.
Full scale output corresponds to either 98 or 140dB, with 22kΩ
minimum load impedance.
This output is suitable for DAT recorders, tape recorders, PC wav
file recording and headphone applications.
AC Input:
10V RMS maximum via “AC Line In” jack socket or via a
CEL-516 Dummy Microphone. Maximum source impedance is
100kΩ .
This input is suitable for inserting direct-line signals from DAT or
tape recorders for analysis.
Optional DC Output:
0 to 2V DC corresponds with 0 to 140dB, with 2kΩ output
impedance.
Internal Clock:
Date and time accuracy better than 2 seconds per day.
Electromagnetic Compatibility:
The instrumentation is designed and tested to comply with the
following EMC and ESD Standards.
IEC 61000-4-2 Testing and Measuring Techniques - Electrostatic
Discharge Immunity Tests,
IEC 61000-4-3 Electromagnetic compatibility (EMC) - Radiated
Electromagnetic Field Tests.
IEC 61000-4-6 Electromagnetic compatibility (EMC) - Immunity to
Conducted Disturbances induced by Radio Frequency Fields.
Tested at 10 V/m or greater.
Page 66 - CEL-450/490 Operators Handbook
Specification
Effects of AC Power Frequency Fields:
Less than ±0.5 dB change in 74 dBA 925 Hz reference level
when subjected to 160 A/m AC magnetic field at 50 and 60 Hz.
Menu Languages:
English, French, German, Spanish, Italian.
Tripod Mounting:
Socket to accommodate standard ¼" Whitworth camera tripod
thread.
Display:
128 x 64 pixel Transflective monochrome LCD.
LED backlight with Manual on/off, timed or keypress operation .
Serial I/O Port:
RS 232 via mini DIN connector and CEL cable.
9600 to 115200 baud, ring indicates auto switch-on provided.
Digital Control:
Remote PC control commands to permit change of instrument
setup, perform in-house testing or to control operation of the
meter’s measurements.
Dimensions:
340 x 100 x 40 mm (13.5 x 4 x 1.5 in) including preamplifier and
microphone.
Weight:
550 gm (19.3 oz) with batteries.
6.2 Measurement Functionality
6.2.1 CEL-450 Versions
Measurement Setups:
Factory determined setup plus 4 user defined setups for each
available operating mode (Broadband, Octave and Third Octave).
CEL-450/490 Operators Handbook - Page 67
Specification
The last (most recently) used set is saved for each mode.
Data Storage:
Cumulative data set of overall values for all user specified
parameters from all available bandwidths for all runs, plus time
history data from up to 4 user specified profiles from the runs.
Measurement Times:
Fixed measurement durations:
1, 5, 10, 15, 20, 30 minutes,
1, 2, 4, 8, 12, 24 hours.
Fixed integration times for profiles:
10, 20, 50, 100, 250, 500 milliseconds,
1, 5, 10, 15, 20, 30 seconds,
1, 5, 10, 15, 20, 30 minutes.
Amplitude weighting (Q):
Selection of Q = 3 plus one other from Q = 4, 5, 6 or none.
Parameters measured:
See Table 2.
Broadband Data Storage:
Manual storage of up to 999 complete sets of results.
Frequency Data Storage:
The memory can save results relating to any measurement
mode (broadband, octave or thirdoctave).
See Table 2 for parameters measured.
Data Recall:
Stored results can be recalled to the display for inspection, even
while a measurement is in progress.
Page 68 - CEL-450/490 Operators Handbook
Specification
Data can be downloaded according to RS 232 standards (or USB
with adaptor) to a PC for further manipulation and report
preparation under the control of dB23 application software.
6.2.2 CEL-490 Versions
In addition to the features listed for the CEL-450, the CEL-490 has the
following.
Measured Parameters:
See Table 2.
Period Timer:
Single period timer from 10 millisecond to 1 hour.
Should be divisible by the profile timer.
The period timer provides a set of period measurements after
each specified period.
Delayed Start/Stop Timers:
7 user specified sets of start and stop times, identified by date
and time to the nearest minute.
L
N
Measurement:
5 L
N
percentile statistics.
CEL-450/490 Operators Handbook - Page 69
Specification
SPL
X
L
(wt)L(wt)mxL(wt)mnL(w)eq
L
(w)v(q)L(p)(pk)L(w)ELEP,dLEP,v
L
Tm3LTm5
L
(wtx)
TWA
,v
L
I(w)eq
LAFL
ZSmxLZSmnLAeq
L
AvgLCpkLCELEP,dLEP,v
L
Tm3LTm5
L
AF99.0%
TWA
,v
L
ICeq
X
X
X
X
X
X
X
X
X
X
Z
C
A
F
3
4, 5, 6
Cum.
Cum.
Period
1 s - 1 hr
Period
10 ms - 1 hr
Profile
10 ms - 30 m
in
I
Displayed
Example
Function
Format
RMS Weigting
Time Weighting
Exchange
Rate Q
Broadband (
-
/
-
)
Narrowband
( / / )
1
1
1
3
Table 2: Functions Available (X) Deepending on Measurement Setup
(Shaded area refers only to CEL-490)
SPLmax
X
X
X
X
X
X
X
X
X
X
X
X
X
SPLmin
X
X
X
X
X
X
X
X
X
X
X
X
X
LEq
X
X
X
X
X
X
X
X
X
X
X
X
X
LEq
I
X
X
X
X
X
X
X
X
LAvg
X
X
X
X
X
X
X
X
X
X
Peak
X
X
X
X
X
X
X
X
X
X
X
X
Single result from selected peak wghtg (Z, C, or A)
SEL
X
X
X
X
X
X
X
X
X
LEPd
X
X
X
X
X
X
X
X
X
Dose time = 8 hours
LEP xhrs
X
X
X
X
X
X
X
X
X
Dose time < > 8 hours
TWA
TWA
TWA
X
X
X
X
X
X
Dose time = 8 hours
TWA xhrs
X
X
X
X
X
X
Dose time < > 8 hours
Taktmax3
X
X
X
X
X
X
X
X
X
X
X
Taktmax5
X
X
X
X
X
X
X
X
X
X
X
HML
HML
HML
X
X
X
X
X
X
X
X
X
HML = L - L (This result can be negative).
Ceq Aeq
LN (x5)
X
X
X
X
X
X
X
X
X
X
X
X
X
5 x L from 0.0 to 100.0% in 0.1% steps
Ns
Histogram
Histogram
Histogram
X
X
X
X
X
X
X
X
X
X
0.5 dB cell width SPL histogram over 140 dB range.
This can be used by dB23 Application Software.
Parameters
SLM Response
Periodic Functions
Notes
S
Notes:
1)
2)
3)
4)
5)
Restrictions on period and Profile function selection.
Maximum of 4 profiles can be selected from those available.
If the Period or Profile interval is 10 ms, then only Leq and SPL functions are available.
The following functions are available only when the Period or Profile time is 1 minute or more: L
N
, L
EP,d
, L
EP,v
, TWA, TWA,
v
.
Taktmax 3 is available when the Period or Profile interval is at least 15 seconds and is a multiple of 3 seconds.
Taktmax 5 is available when the Period or Profile interval is at least 10 seconds and is a multiple of 5 seconds.
v04015
Page 70 - CEL-450/490 Operators Handbook
Specification
7. PARTS & WARRANTY
7.1 Schedule of Parts
A complete CEL-450 Sound Level Meter consists of:
CEL-450 Sound Level Meter,
Plus as applicable:
CEL-250 Class 1 WS2 (
1
/2“) Electret Microphone
(or MK 250), CEL-495 Class 1 Preamplifier, or CEL-485 Class 2 WS3 (
1
/4“) Electret Microphone in a
Preamplifier Assembly. The following additional items are also included: 016004 (4 off) Alkaline-Manganese Battery 1.5 V (IEC LR6), HB3307 CEL-450/490 Operator’s Handbook.
A complete CEL-490 Sound Level Meter consists of:
CEL-490 Sound Level Meter,
Plus as applicable: CEL-250 Class 1 WS2 (
1
/2“) Electret Microphone
(or MK 250), CEL-495 Class 1 Preamplifier, or CEL-485 Class 2 WS3 (
1
/4“) Electret Microphone in a
Preamplifier Assembly. The following additional items are also included:
016004 (4 off) Alkaline-Manganese Battery 1.5 V (IEC LR6), HB3307 CEL-450/490 Operators Handbook,
When the instrument is delivered, check all of the above items have been supplied. The following standard accessories may be ordered separately.
CEL-110/1 Acoustic Calibrator Class 1 CEL-110/2 Acoustic Calibrator Class 2C (Includes CEL-4726
Microphone Adaptor), CEL-2962 Windshield for Class 1 Microphones, CEL-4672 Windshield for Class 2 Microphones, CEL-6813 dB23 Download Software on a singleCD C6724/2 Communication Cable to PC.
Parts & Warranty
CEL-450/490 Operators Handbook - Page 71
7.2 Instrument Servicing & Warranty
To ensure its conformity with the specification, this instrument is thoroughly inspected and it’s accuracy verified prior to dispatch. All technical information is filed under the instrument serial number, which should, therefore, be quoted in any correspondence.
The manufacturers undertake to rectify any defect in the instrument that is directly attributable to faulty design or assembly, and which becomes apparent during the warranty period. In order to take advantage of this warranty, the instrument must be returned, carriage paid, to the manufacturer’s factory or accredited agent, where necessary repairs will be carried out.
The warranty period runs for 24 months from the date of receipt of goods, with exceptions on certain specialised components supplied by other manufacturers which may be warranted for shorter or longer periods by their actual manufacturers. In all such cases, the benefit of these undertakings will be passed on to the user.
CASELLA CEL liability is limited to items of their own manufacture, and they do not accept liability for any loss resulting from the operation or interpretation of the results from this equipment.
To obtain repair under warranty, the instrument should be packed and returned in it’s original packing or an equivalent either to CASELLA CEL’s local agent, or in the case of domestic sales, to the CASELLA CEL Service Department at Bedford. Please include the following information:
Instrument Type(s), Serial Number(s) and Firmware Version
Number(s),
Customer name and address,
Contact name and phone number,
Details of any PC and Software involved, including Version
Number(s),
Reason for returning the equipment with a detailed description
of the fault,
List of any error messages that may have been displayed.
The necessary adjustments or repairs will be carried out, and the instrument returned as soon as possible.
Parts & Warranty
Page 72 - CEL-450/490 Operators Handbook
A comprehensive Instrument Calibration Maintenance Agreement (ICMA) scheme is available to extend the initial warranty period of this instrument. At the end of the first warranty period, it is recommended that the equipment be returned to the Service and Verification Department at Bedford, where it will be inspected and entered into the ICMA scheme as required. The warranty will then be extended for the period stated on the individual schedule. Please contact your local CASELLA CEL agent for full details of this service.
After the warranty has expired (except on approved accounts) service work is undertaken against quotations, and all packing and transit costs are charged extra.
CEL instrumentation and software is designed, manufactured, and serviced by:
CASELLA CEL LIMITED
and
CASELLA CEL INC.
CASELLA Group of Companies
Parts & Warranty
CEL-450/490 Operators Handbook - Page 73
Parts & Warranty
Page 74 - CEL-450/490 Operators Handbook
Parts & Warranty
CEL-450/490 Operators Handbook - Page 75
Dose Results Freq. (Hz)
Periodic Periodic Functions Functions
SLM Response SLM Response
1/4 1/4
Time Weight F Peak Weight Z Exchange Q 3
RMS Weight A
1/4
Broadband
CEL-490 Broadband only
Narrowband
CEL-450 & CEL-490 REAL-TIME SOUND LEVEL METERS Menu Structure
ZIZ84.6
L
dB
16k Hz
dB
4k
1k
2506316
ACZ
AFmx
dB
AF
Aeq
AFmn Zpk
LL
L
L
L
0140
dB
Broadband
Measure
Calibrate
Obtain Menu
Narrowband
L
ZF
Calibration Timers
Memory Configure Status
2/7
Measure Mode
Setup
8Ø - 19ØØ28A - NN Preamp
CEL49Ø.C1 vNN.NN
I/O ID:
Type 1 None NNNNNN
2Mb
13JanØ4 1Ø:54:42
1%
2
Format
Memory
Full
Runs
512Kb
13JanØ4 1Ø:54:42
1% 2
Memory Full Runs
Setup
Press MENU
User Setup 1
Key to Start
Language Backlight
RS232 Comms
RS232 Comms
Graph Range
Time & Date Microphone AC Output
1/7
Delete Current Delete All
View Current
View All
1/4
Tue
Thu
Wed 7 Jan2ØØ4
9 Jan2ØØ4
13 Jan2ØØ4
13 Jan2ØØ4
15 Jan2ØØ4
Fri
Tue
Thu
Wed 7 Jan2ØØ4
9 Jan2ØØ4
13 Jan2ØØ4
13 Jan2ØØ4
15 Jan2ØØ4
Fri
1
3
Third Octave
Broadband
Octave
2/3
User Setup 2 User Setup 3
User Setup 4
Factory Setup
User Setup 1
User Setup 1
2/5
More Options
More Options
Runs
Runs
Instrument Version:
A=Broadband B=Octave
C=Third-octave Type1or2 Firmware version Program and version Instrument ID
XX XX XX
v04011
7Ø
8 Hours
EP,d
L
WA
T&
Threshold
1/2
Profile ----­Max Run Time 45 Days 11:26:ØØ
Period 1min
1/4
CASELLA CEL Ltd, 2004
Cel 490
Profile Parameters CEL-490 Broadband Models only
Dose Parameters CEL-490 Broadband Models only
L
L LL
AFmx
LL
1/15
More Parameters
Aeq
Zpk
AFmn
LL
Cumulative: 10 Narrow­band 15 Broadband Parameters Period: 9 Narrow­band 15 Broadband Parameters
Periods: 13 Selectable Between 10 ms and 1 min
Periods: 13 Selectable Between 10 ms and 1 min
L
L LL
AFmx
LCum L
1/2 1/15
-----
More Parameters
More Parameters
Aeq
Zpk
AFmn
CUM
PER
LPeriod
Profile
L
Delay Timer
Timers Off
1/3
Sync Timer
1/2
12hr
Duration
Duration Timer
Duration Timer
Ø9JanØ4 11:28
114.ØdBAuto
40
80
120
Menu Structure
CEL-450/490 Operators Handbook - Foldout
Thank you for reading this data sheet.
For pricing or for further information, please contact us at our UK Office, using the details
below.
UK Office
Keison Products,
P.O. Box 2124, Chelmsford, Essex, CM1 3UP, England.
Tel: +44 (0)330 088 0560 Fax: +44 (0)1245 808399
Email: sales@keison.co.uk
Please note - Product designs and specifications are subject to change without notice. The user is responsible for determining the
suitability of this product.
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