April 2004 CEL-450 & CEL-490 REAL-TIME SOUND LEVEL METERS Provisional Handbook HB3307.01 CASELLA CEL Regent House, Wolseley Road Kempston, Bedford MK42 7JY, U.K. CASELLA USA 17 Old Nashua Road #15 Amherst NH 03031, U.S.A. Phone: Fax: E-mail: Web: Toll Free: +1 800 366 2966 Fax: +1 603 672 8053 E-mail: info@casellausa.com Web: www.casellausa.com +44 (0) 1234 844 100 +44 (0) 1234 841 490 info@casellagroup.com www.casellagroup.
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Contents 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.
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Contents Contents Chapter . . . . . . . . . . . . . . . . . . . Page 1. INTRODUCTION 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2. 3.2 3.3 3.3.1 3.3.2 . . . . . . . . . . . . . . . . . . . . 7 . . 9 . 10 . 10 . 12 . 14 . 15 . 16 . 17 Select Instrument Configuration (Language, Microphone Response Etc.) . . . . . . . . . . . . . 19 Select Measurement Mode (Bandwidth) . . . . . . . . . . . . . . . . Select Run Timing . . . . . . . . . . . . . Select Measurement Setup (Factory- or User-Prepared Setups) . . .
Contents Chapter . . . . . . . . . . . . . . . . . . . Page 5.3 5.4. 5.5 . . . . . . . . . . . . . . . . 56 57 . . . . . . . . . . . . . . . . . . . . . . . . 58 59 61 SPECIFICATION . . . . . . . . . . . . . . . . . . 63 6.1 6.2 6.2.1 6.2.2 . . . . 63 67 67 69 . . . . . . . . . . . . . . 71 Schedule of Parts . . . . . . . . . . . . . . . . . . Instrument Servicing & Warranty . . . . . . . . . . 71 72 4.5.1 4.5.2 6. 7. Delete Stored Data . . . . . . . . . Format Memory . . . . . . . . . . .
Introduction 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.
Introduction 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.
Introduction Figure 2: Quick edit functions 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.
Introduction 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.
Introduction Inst. Type Inst. Version 450/490 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 At the end of the self test sequence, the instrument displays memory information and battery voltage, Current date and time followed by the identity of the last used setup. Last used setup Finally it enters calibration check mode (described in Chapter 2).
Introduction 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.
Introduction Figure 4: Simplified menu structure (Some of these options may not be available on all versions) 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.
Introduction 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 Meters 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.
Introduction LAvg HML Profiles the total LAvg 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. Average level over the measurement period. This value is the calculation: LCeq - LAeq . Up to 4 parameters can be selected to have their profile stored. Period times between 10 ms and 30 minutes can be selected.
Introduction 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.
Introduction 1.9 dB23 SoundTrack Software The CEL-6811 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.
Introduction 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 menu1 shows that option 3 has been selected from the 5 available. 6. Settings left highlighted on a menu screen become the active options.
Preliminary Operations 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.
Preliminary Operations Operation 3. Select the Configure option Press Display Shows or 4. Move to the Configure menu 5. Select the Language option 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. or 6.
Preliminary Operations Operation Press Display Shows 8. Select the required microphone response (and other configuration items) in the same way. Comments The highlighted entries will be used. These settings will also be stored and used next time the instrument is switched on. Date and time are set using the quick edit function as follows. 9. Select the date and time option by moving the reverse video cursor to the required line on the Configure menu. 10.
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Select Mode & Setup 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 1. Start from the Main menu 2. Select the Measure Mode option Comments This is the Main menu screen. Move the reverse video cursor to the required line. and 3.
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.
Select Mode & Setup Operation Press 2. Select the Timers option and 3. Move to the Timers menu 4. If required select followed Duration Timer from by Timers menu Display Shows Comments Move the reverse video cursor to the required line.
Select Mode & Setup Operation 5. If required, set Duration and Sync Timer Press Display Shows to enable quick edit mode. Comments Use field. and to select a Use and to change the entry in the field. Save the settings by pressing again to resume normal operation. 6. When a CEL-490 is followed being used, if by required select Delay Timer from the Timers menu 7. Select second Delay Timer menu 8. If required, set the Delay Timer to enable quick edit mode Press to return to the Timers menu.
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 that are to be measured.
Select Mode & Setup Operation Press Display Shows Comments 2. Display the Main menu, and then select or Setup 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.
Select Mode & Setup Operation Press 7. Select or Functions from the Setup then screen to enable Cumulative parameters to be set Display Shows Comments 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.
Select Mode & Setup Operation 9. If required, enable (√) or disable (X) the functions Press Display Shows to enable quick edit mode Comments Use field. and to select a 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 Mode & Setup Operation Press 11. Select Period and Profile Functions from the Period Setup screen 12. If required, enable (√) or disable (X) the functions Display Shows Comments 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 HML functions are not available, LAF LTm5 LAFmx LAFmn LAF10.0 LAF50.0 LAeq LZpk LAF90.
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 LEP,8h and TWAV 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 to settings enable quick edit mode Use field. and to select a Use and to change the entry in the field.
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 then select or Setup 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.
Select Mode & Setup Operation Press Display Shows 6. Select or Functions from the Setup then screen to allow measurement parameters to be set Comments 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.
Select Mode & Setup Operation Press 9. Select Period from the Setup screen to enable measurement intervals to be set or then Display Shows Comments 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.
Select Mode & Setup Operation 12. Select Frequency from the Setup screen to change the range of frequency bands measured 13. If required, change the range of frequency bands measured Press Display Shows or then to enable quick edit mode Comments This screen allows the range of frequency bands measured to be restricted to a particular range of interest. Use field. and to select a Use and to change the entry in the field. Save the settings by pressing again to resume normal operation.
Acoustic Calibration Check 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.
Acoustic Calibration Check DO NOT remove the protective metal grid from Class 1 microphones. With a WS2, 1/2" microphone, fit the calibrator directly on to the microphone, making sure it is pushed firmly into contact with the stop in the calibrator cavity (Figure 5). With a WS3, 1/4" microphone, fit the coupler, supplied with the calibrator, on to the microphone making sure it is pushed firmly into Figure 5: Fitting the acoustic calibrator contact with the stop in the coupler cavity (Figure 5).
Acoustic Calibration Check 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. 3. Switch the Calibrator ON This shows the level determined by the sound level meter. 4. When the correct calibration level should be 114.0 dB Press to return.
Acoustic Calibration Check Operation Press Display Shows 5. When the calibration is successful Comments 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. 6. Change the Automatic calibration level Highlight the Auto calibration level.
Acoustic Calibration Check Operation Press Display Shows 7. Edit the Automatic calibration level Comments 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 Highlight LZF again. or 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.
Acoustic Calibration Check Operation Press Display Shows 3. Select Manual calibration Comments This is the manual calibration check screen. It shows the current sound level and details of the last calibration. If the Calibration screen shows a “Scale ... ” line instead of “Manual”, the last calibration was performed via line input (see Section 5.5). 4. Return the highlight to LZF or This allows the displayed level to be changed manually. 5.
Acoustic Calibration Check Operation Press 8. When the level is correct 9. Save the calibration Display Shows Comments To allow the new setting to be saved as the current calibration4. 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.
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Operation 5. OPERATION 5.1 Measurement With the instrument configured, calibration checked, timers set and measurement parameters specified as described in the preceding chapters perform measurements as described in this chapter. 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 1.
Operation Operation Press Display Shows 5. When the Measurement screen looks like this Comments 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.
Operation Operation Press Display Shows Comments Setting the Delay timer is described in Section 3.1. 4. Inspect stored data (If required, press to abort the run and return to step 2.) 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.
Operation Operation Press Display Shows Comments Press readout. to add a cursor 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.
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 1.
Operation Operation Press Display Shows 2. If required, change the measureto ment enable functions quick edit mode Comments The measurement functions can be selected as follows. All broad and narrow bands: F, S or I time weigting with A, C or Z frequency weighting, so that pre-weighted frequency analysis can be performed. Use field. and to select a Use and to change the entry in the field. Then save the settings by pressing to resume normal operation. 3.
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.
Operation Operation Press Display Shows 10. Inspect further stored data Comments This screen shows the cumulative spectrum saved for the first measurement parameter (in this example LZImx). and may be used to inspect other data screens saved for the run, for example cumulative data from other functions and period data. This screen shows a period spectrum saved for the first measurement parameter (in this example LZImx). 11.
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. 16. When the sound to be excluded has stopped Data collection is resumed and the run icon displayed. 17. When sufficient data has been collected can be used to pause measurement only from a Run screen.
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 1. Start from the Main menu 2. Select the Memory option or 3. Move to the Memory menu 4. Move to the list of run Dates for the specified bandwidth and select the required date Comments This is the Main menu.
Operation Operation Press 5. Move to the list of then Runs and select a run or 6. View the Header for the required run Display Shows Comments This is a directory of all runs stored on the specified date with the required bandwidth. 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.
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 1. Start from the Main menu 2. Select the Memory option Comments This is the Main menu.
Operation Operation Press 4. Move to the list of run Dates for the specified bandwidth and select the required date Display Shows then or 5. Move to the list of then Runs and select a run or Comments 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.
Operation Operation Press Display Shows Comments 1. Start from the final Self Test screen. This screen offers the Format option. 2. When re-format is required This screen asks for confirmation. Perform Step 2 before the option is replaced by the Battery Voltage line and the calibration or menu screens. 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.
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.
Operation Figure 6: Bottom panel of the instrument 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.
Operation 1. Start from the sound level meter Line Input Calibration screen Broadband LZF 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.
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.
Specification 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 197, IEC 60804: 1985, ANSI S1.4: 1983, ANSI S1.
Specification Total linear A-weighted measurement range: 25 to 140dB. 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. RMA 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.
Specification Effect of Temperature: Electrical accuracy of the instrument over -10 to +50o C: < ±0.2 dB Temperature coefficient of CEL-250 Microphone: 0.02 dB/oC. 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.
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 14 VDC at typically 150 mA with 1000 mA inrush current. AC Output: Approximately 0.5 VRMS via “AC Line Out” jack socket. Full scale output corresponds to either 94 or 114 dB, with 22 kW minimum load impedance.
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" 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.
Specification 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.
Specification 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 to the nearest minute. LN Measurement: 5 LN percentile statistics.
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Parts & Warranty 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: 1 CEL-250 Class 1 WS2 ( /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.
Parts & Warranty CEL-4672 CEL-282 CEL-284/2 C6724 Windshield for Class 2 Microphones, Acoustic Calibrator Class 2L (Includes CEL-4725 Microphone Adaptor), Acoustic Calibrator Class 1L (Includes CEL-4725 Microphone Adaptor), Communication Cable to PC. 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.
Parts & Warranty 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. A comprehensive Instrument Calibration Maintenance Agreement (ICMA) scheme is available to extend the initial warranty period of this instrument.
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Menu Structure CEL-450/490 Operators Handbook - Foldout
