Casella CEL CEL-63X - Manual (Page 78)

CEL-63x Environmental & Occupational Noise Meter
78 Casella CEL
13. Electric field strength greater than 10 V/m
The CEL-63x instrument has not been tested for field strengths greater than
10 V/m.
14. EMC emissions
When tested, emissions from the CEL-63x instrument were no greater in one
plane or in any mode of operation than another.
15. EMC susceptibility
The CEL-63x instrument has a slightly higher
susceptibility with the Y direction facing the radiating
antenna.
X is the direction of the microphone
Y is the direction to either side of the case
Z is the direction perpendicular to the surface of
the display
10.1 Sound calibrators – Level corrections
Sound level calibrators apply sound pressure to a microphone in a closed cavity.
The microphone‟s response in a free field to a 1 kHz tone will be slightly
different from that of a pressure field. Also, some calibrators are affected by the
physical size of the microphone changing the volume of the calibrator‟s cavity.
The wind screen has an effect on the free-field response at 1 kHz. However, this
can be compensated during calibration.
Table 6. Calibration corrections for the CEL-251 and CEL-252
microphones
Calibrator
Calibration Level
Correction no Wind
Screen
Calibration Level
Correction with
Wind Screen IEC 60942
Casella CEL-110/1 -0.1dB 0.0dB Type 1
Casella CEL-110/2 -0.1dB 0.0dB Type 2
Bruel & Kjear 4231 -0.1dB 0.0dB Type 1 approved
Cirrus CR:515 -0.1dB 0.0dB Type 1 approved
Examples
The CEL-63x instrument can be calibrated at a nominal level of 94 dB or
114 dB, depending on the type of calibrator used.
If you use a CEL-120/1 or CEL-120/2 calibrator and the certified output
from the calibrator is 113.98 dB, and you intend to use the instrument