Casella CEL CEL-272 User Manual

Page 4

ACOUSTIC CALIBRATION

Perform an acoustic calibration with a CEL-282
(Class 2) or CEL-284/2 (Class 1) Acoustic Calibra-
tor immediately before use.

Caution!

Calibration resets the store, if calibrating
after use, first make a note of the display
indication.

1. If necessary, use the 1.5mm Allen Key to retract

the locking screw and free the instrument
covers.

2. Slide the upper instrument cover outwards in the

groove to expose the control switches as
shown.

3. Fit the CEL-6048 Microphone Coupler into the

Calibrator.

4. Push the microphone firmly into the Coupler

cavity.

5. Slide the Battery switch to either Pa

h or

% Dose position.

6. Slide the Display switch on the CEL-272 to the

CAL position. A flashing decimal point indicates
CAL mode.

7. Switch the Calibrator ON.

8. Wait approximately 20 s for the instruments to

stabilise.

If LO BAT is indicated change the batteries.

9. If necessary, carefully use the PP38054 Trimtool

provided to turn the ADJ control until the
display shows 0152.

THIS INDICATION IS NOT A LEVEL IN dB.

10.Switch the Calibrator OFF and remove both it

and the Coupler.

11.Return the Display switch to ON or OFF as

required.

12.Replace the cover and if required, refasten the

locking screw to secure the covers.

Other calibrators are not recommended for field
calibration, as no other suitable acoustic coupler is
available. The calibration of the CEL-272 and the
calibrator used should be verified at least every

year. Please contact Lucas CEL at Hitchin for de-
tails of their calibration services.

OPERATION

1. Insert batteries as described above.

2. Calibrate the instrument acoustically as

described above.

3.. Slide the upper cover open.

4. Slide the display switch to ON or OFF.

5. Either: Slide the Battery switch to Pa

h to

measure Sound Exposure.

Or: Slide the switch to % Dose to measure
Noise Dose.

The instrument starts measuring the selected
parameter as soon as this switch has been set.

6. If necessary for security reasons, slide the

Display switch to OFF to suppress indication.

It will still indicate which parameter is being
measured, and the occurrence of an overload
or low battery level.

7. Replace the cover and if required refasten the

screw.

8. Clip the microphone as close to the wearer's ear

as possible. ISO 1999: 1990 stipulates 10 cm

1 cm.

In some circumstances it may be possible to
wear the microphone clipped to safety
spectacles, on a helmet, or on ear defenders. A
more comfortable location may be found on
a lapel or the shoulder of a garment.

9 Put the instrument in a convenient pocket, or clip

it to the wearer's belt or waistband.

It is suggested that the instrument and micro-
phone be WORN AT ALL TIMES throughout
the working day. However, a projected
exposure can be calculated from typical
representative sample periods.

10.Make a note of the results at the end of each

working period.

11.Switch the instrument OFF (Battery switch to

OFF) when not in use.

12.Remove batteries when out of service for long

periods.

4 Black

4 CEL Blue