Casella CEL CEL-440 - Manual (Page 60)

The temperature correction to be applied for CEL-250 and
MK 250 Type 1 microphones:
Corrected level = Actual level - 0.02 (t - 20)
Where t is temperature
o
C.
The temperature correction to be applied for CEL-485 Type 2
microphone/preamplifier unit is applied automatically by the
preamplifier.
Storage range: -20 to +60
o
C.
Effects of Humidity:
Less than 0.5 dB over the range 30 to 90% relative humidity
(provided there is no condensation), relative to the value at
65% RH and 40
o
C.
Storage range: 0 to 90%RH in the absence of condensation.
Effects of Magnetic Fields:
Less than 3 dB(A) above the minimum valid reading when tested
according to IEC 60651 clause 8.4 at 50 Hz.
Effects of Vibration:
Less than 6 dB when tested according to IEC 60651 clause 8.3.
Effect of Operator:
Negligible on free field measurements when standing more than
2 m behind the SLM.
Tripod mounting:
Socket to mount on standard 1/4" camera tripod thread.
Battery Life:
At least 14 hours in broad band mode when using LR6 battery.
External Power:
9 to 14 V DC at typical 150 mA.
The batteries may safely be left in the instrument while it is
operating from an external supply. Remove the batteries when
the instrument is to be out of service for some time. A built in
lithium battery will maintain stored data and set ups.
Page 60 - CEL-440/480 Operators Handbook
Specification