2 acoustic calibration – Casella CEL CEL-281 User Manual
Page 12

4.
If an incorrect time weighting for the required measurements is
indicated at "TC=?", go to Section 1.3.3: Set Time Weighting.
5.
If an incorrect frequency weighting for the required measure-
ments is indicated at "dB?", go to Section 1.3.4: Set Frequency
Weighting.
6.
When the indicated time and frequency weightings are satis-
factory, press the
key.
The CEL-281 starts to collect data at the next whole clock
minute.
1.3.2 Acoustic Calibration
Check the acoustic calibration immediately before making measure-
ments with the CEL-281. (Note that calibration AFTER measurement
overwrites the initial calibration level used in any printout via a PC pro-
gram.
Use a CEL-282 Acoustic Calibrator (Class 2) or a CEL-284/2 Calibrator
(Class 1); both provide a nominal 114.0 dB at 1 kHz.
1.
Push the microphone firmly into the cavity of CEL-6050 Coupler
supplied.
2.
Push the coupler and microphone firmly into the calibrator cavity.
3.
Use the 1.5 mm Allen K ey to retract the locking screw and free
the lower sliding cover.
4.
Switch the CEL-281 ON.
CAL is displayed and blinks for 20 s. If calibration is not initiated
within this period, the CEL- 281 becomes fully operational us-
ing the settings stored from last time of operation.
Page 4 - CEL-281 Operator's Handbook
Getting Started_