CASELLA CEL CEL-450 Technical Information

April 2004CEL-450 & CEL-490REAL-TIMESOUND LEVEL METERSProvisional HandbookHB3307.01CASELLA CELRegent House, Wolseley RoadKempston, BedfordMK42 7JY

1.3 Install Microphone, Preamplifier & BatteriesScrew the Class 1 microphone “finger tight” on to the preamplifier. Withthe instrument switched OF

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.

2. Press to switch the instrument OFF when all measurement, setup and data recall operations are finished.1.5 DescriptionBoth the CEL-450 and CEL-49

Simple procedures allow a measurement setup to be selectedand the instrument to make the required measurements and save themautomatically in separate

These instruments are constructed to withstand some of thetoughest industrial conditions with cases formed from a polyester/polycarbonate material, gi

the total LAvg of a person’s workplace noiseexposure averaged over a user selected(variable) period of hours and minutes. This unit is specified in th

run timing facilities. These allow it to operate with user set delayed startand stop times, and to store period results taken at regular intervals.1.8

1.9 dB23 SoundTrack SoftwareThe CEL-6811 dB23 Software enables data collected by the CEL-450 andCEL-490 to be downloaded to a PC for storage, manipula

Hints For Using Menus1. and displayed on a menushow which option keys are active.2. In general, and keys move thereverse video cursor fro

2. PRELIMINARY OPERATIONS2.1 Select Instrument Configuration(Language, Microphone Response Etc.)Select the language in which the instrument will prese

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Operation Press Display Shows Comments3. Select theConfigureoption or Move the reverse videocursor to the required line.4. Move totheConfiguremenuThis

Operation Press Display Shows Comments8. Select the required microphone response (and otherconfiguration items) in the same way.Date and time are set

Page 22 - CEL-450/490 Operators HandbookPreliminary Operations

3. SELECT MEASUREMENT MODE,TIMER SETTINGS, & SETUP3.1 Select Measurement Mode (Bandwidth)The measurement mode specifies the bandwidth that is to b

Duration Run for a predetermined duration after pressing the run key. This can be used to time a workshift, or to measure some particularly noisyopera

Operation Press Display Shows Comments2. Select theTimersoptionand Move the reverse videocursor to the required line.3. Move tothe TimersmenuThe Timer

Operation Press Display Shows Comments5. If required,setDurationand SyncTimertoenablequickeditmode.Use and to select afield.Use and to changet

When the required timer settings have been selected, press onceto obtain a Measurement screen or twice to obtain the Main menu thatgives access to a

Operation Press Display Shows Comments2. Display theMainmenu, andselectSetupthen orThis is the Main menuscreen with the reversevideo cursor highlighti

Operation Press Display Shows Comments7. SelectFunctionsfrom theSetupscreen toenableCumulativeparametersto be set orthenThis screen allows selectionof

Warnings !LOAD BATTERIES following the instructions given inSection 1.3. Make sure they are inserted in the orientationsshown inside the battery compa

Operation Press Display Shows Comments9. If required,enable (√)or disable(X) thefunctionstoenablequickeditmodeUse and to select afield.Use and

Operation Press Display Shows Comments11. SelectPeriod andProfileFunctionsfrom thePeriodSetupscreenThe Period and Profilefunctions are set in thesame

Operation Press Display Shows CommentsThe dose normalisationperiod is the duration towhich the actual dosemeasurements are“normalised” to givecomparab

Operation Press Display Shows Comments1. SelectOctave orThirdOctaveMeasure-ment asdetailed inSection 3.1The highlighted option willbe the bandwidth us

Operation Press Display Shows Comments6. SelectFunctionsfrom theSetupscreen toallowmeasure-mentparametersto be set orthenThis screen allows selectiono

Operation Press Display Shows Comments9. SelectPeriodfrom theSetupscreen toenablemeasure-mentintervals tobe set orthenThis screen allows a periodto be

Operation Press Display Shows Comments12. SelectFrequencyfrom theSetupscreen tochange therange offrequencybandsmeasured orthenThis screen allows the r

4. ACOUSTIC CALIBRATION CHECK4.1 Start Acoustic Calibration CheckIt is recommended that a calibration check of the microphone be madeboth before and a

DO NOT remove the protective metal grid from Class1 microphones.With a WS2, 1/2"microphone, fit thecalibrator directly on tothe microphone, makin

Operation Press Display Shows Comments1. Start withthe AutocalibrationscreenThis is the Automaticcalibration check screen. It shows the current soundl

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Operation Press Display Shows Comments5. When thecalibrationissuccessfulThe user is given the optionof saving or not saving thenew calibration.Press

Operation Press Display Shows Comments7. Edit theAutomaticcalibrationlevelPress or to changethe level over the range 85.0to 130.0 dB in 0.1 dB ste

Operation Press Display Shows Comments3. SelectManualcalibrationThis is the manual calibrationcheck screen. It shows thecurrent sound level anddetails

Operation Press Display Shows Comments8. When thelevel iscorrectTo allow the new setting tobe saved as the currentcalibration4.9. Save thecalibration

Page 44 - CEL-450/490 Operators HandbookAcoustic Calibration Check

5. OPERATION5.1 MeasurementWith the instrument configured, calibration checked, timers set andmeasurement parameters specified as described in the pre

Operation Press Display Shows Comments5. When theMeasure-mentscreenlooks likethisThe last setup used wasnarrow band.When narrow bandmeasurement with B

Operation Press Display Shows CommentsSetting the Delay timer isdescribed in Section 3.1.(If required, press toabort the run and return tostep 2.)4.

Operation Press Display Shows CommentsPress to add a cursorreadout.Now use and tomove the cursor and and to change thedB scaling.Press agai

Operation Press Display Shows CommentsStop Run: End run and store data (goto Step 1).Restart Run: Abort current run and start anew one (return to Step

ContentsChapter . . . . . . . . . . . . . . . . . . . Page1. INTRODUCTION . . . . . . . . . . . . . . . . . . 7

Operation Press Display Shows Comments2. If required,change themeasure-mentfunctionstoenablequickeditmodeThe measurement functionscan be selected as f

Operation Press Display Shows Comments6. Return tothemeasure-mentscreen 7. Start ameasure-ment run(i.e. storedata) shows that a run is inprogress.Pres

Operation Press Display Shows Comments10. Inspectfurtherstored dataThis screen shows thecumulative spectrum savedfor the first measurementparameter (i

Operation Press Display Shows Comments15. If somesoundoccurs thatmust beexcludedfrom thefrequencymeasure-ment indicates that datacollection is paused

5.2 Recall Stored DataData stored in the instrument can be recalled to the display forinspection. This allows the operator to check the quality of res

Operation Press Display Shows Comments5. Move tothe list ofRuns andselect a runthen or This is a directory of all runsstored on the specified datewith

Operation Press Display Shows CommentsPress then use and to scan theband levels manually.Press to cancel.Press and to displayfrequency data

Operation Press Display Shows Comments4. Move tothe list ofrun Datesfor thespecifiedbandwidthand selecttherequireddatethen or This menu shows the date

Operation Press Display Shows Comments1. Start fromthe finalSelf Testscreen.This screen offers theFormat option.Perform Step 2 before theoption is rep

4.5.1 RecordingDAT recorders have a typical dynamic range of 70 dB, while analogrecorders often have less. To ensure the maximum dynamic range forreco

Chapter . . . . . . . . . . . . . . . . . . . Page5.3 Delete Stored Data . . . . . . . . . . . . . . . . . 565.4

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

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

The instrument replay scale now matches the scale used for the recording so that the levels indicated by the display will becorrect.10. Press to dis

6. SPECIFICATION6.1 GeneralStandards:The CEL-450/490 series are self contained sound level metersdesigned to comply with the following international s

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

Effect of Temperature:Electrical accuracy of the instrument over -10 to+50oC: < ±0.2 dBTemperature coefficient of CEL-250 Microphone: 0.02dB/oC.Eff

Remove the batteries when the instrument is to be out ofservice for some time. A built in lithium battery will maintainstored data and setup informati

Effects of AC Power Frequency Fields:Less than ±0.5 dB change in 74 dBA 925 Hz reference levelwhen subjected to 160 A/m AC magnetic field at 50 and 60

Data Storage:Cumulative data set of overall values for all user specifiedparameters from all available bandwidths for all runs, plus timehistory data

6.2.2 CEL-490 VersionsIn addition to the features listed for the CEL-450, the CEL-490 has thefollowing.Measured Parameters:See Table 2.Period Timer:Si

1. INTRODUCTIONPlease read Sections 1.1 to 1.4 before commencing measurement. For aquick introduction to instrument operations, Chapter 4 may be used

Page 70 - CEL-450/490 Operators HandbookSpecification

7. PARTS & WARRANTY7.1 Schedule of PartsA complete CEL-450 Sound Level Meter consists of:CEL-450 Sound Level Meter,Plus as applicable:CEL-250 Clas

CEL-4672 Windshield for Class 2 Microphones,CEL-282 Acoustic Calibrator Class 2L (Includes CEL-4725Microphone Adaptor),CEL-284/2 Acoustic Calibrator C

Reason for returning the equipment with a detailed descriptionof the fault,List of any error messages that may have been displayed.The necessary adjus

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Parts & WarrantyCEL-450/490 Operators Handbook - Page 75

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Menu StructureCEL-450/490 Operators Handbook - Foldout

The broadband screen in Figure 1 shows one principal and foursubordinate parameters, where the principal parameter is a level asidentified below.The f

1.2 Quick EditAll control functions for the CEL-450 and CEL-490 are accessed via menudisplays. In addition a powerful Quick Edit facility can be invok