Casella CEL CEL-62X - Manual (Page 32)

Casella CEL Limited 32
e) Linear Operating Range
The lower and upper limits of the linear operating ranges for electrical input, or
using a CEL-251 microphone; (add 10dB to the lower limit when using a CEL-252
microphone)
Weighting 31.5 Hz 1 kHz 4 kHz 8 kHz 12.5 kHz
A 30 to 100 30 to 140 30 to 141 30 to 138 30 to 134
C 32 to 137 32 to 140 32 to139 32 to 136 32 to 132
Z 38 to 140 38 to 140 38 to 140 38 to 140 38 to 140
C Peak 65 to 140 65 to 143 65 to 142 65 to 139 65 to 135
f) Linearity Measurements Starting Point
The starting point for measuring level linearity errors is 114dB.
g) Electrical Input
The input device to apply electrical signals to the pre-amplifier is a series 18pF
+/- 5% capacitor. The CEL-516-02 can be used for this purpose. The electrical
self generated noise can be measured with the supplied shorting plug attached to
the CEL-516-02.
h) Self Generated Noise
Combination of CEL-251 microphone thermal noise and meter electrical noise.
Weighting Electrical
Typical dB
Electrical
Max dB
Microphone
Thermal dB
Combined
Typical dB
Combined
Max dB
A 18.0 20.0 16.0 20.0 22.0
C 21.0 23.0 16.8 22.0 24.0
Z 28.0 30.0 16.8 28.0 30.5
Note: The CEL-252 microphone has a thermal noise of typically 20dBA – the
combined typical and max noise levels will be 1.5dB higher than above.
i) Highest Level
The highest sound pressure level designed to be measured by the CEL-62X
sound level meter when fitted with a 50mV/Pa microphone is 140dB. The highest
peak to peak voltage that can be applied to the pre-amplifier input via the CEL-
516-02 is 28.5V.
j) Power Supply Voltage Range
The CEL-62X can be powered from three internally fitted AA batteries, or an
external 12VDC supply (2.1mm connector, tip +ve), or 5VDC USB supply from a
PC.
Internal batteries – range 3 to 5 volts. The battery condition symbol will start to
flash as a warning when the batteries have discharged to 3.3 volts, and the meter
will stop a run and turn off when the batteries have discharged to less that 3 volts
to ensure no data is measured that does not meet the requirements of IEC
61672.