Casella CEL CEL-281 - Manual (Page 76)

Normally, calibration will be undertaken using either a CEL-282 Acoustic
Calibrator (IEC 942 Class 2L) or a CEL-284/2 Acoustic Calibrator (Class
1L), both of which generate a nominal 114.0 dB and 1 kHz at standard
temperature and pressure.
While performing an acoustic calibration, the maximum noise level in the
area must be at least 20 dB below the generated calibration level. Pro-
ceed as follows.
1. Prepare the dosimeter for use by installing and/or checking
batteries as described above.
2. Push the microphone firmly into the CEL-6050 Microphone
Coupler supplied with the CEL-281 (refer to Figure 14).
Make sure that the microphone is correctly seated in the cavity.
3. Push the microphone coupler firmly into the calibrator cavity
(Figure 14).
910012 Calibrator
'O' Ring
Shoulder
'O' Ring
Microphone Coupler
Shoulder
Microphone
Figure 14: Fitting the coupler and acoustic calibrator
Preparation
CEL-281 Operator's Handbook - Page 67