Casella CEL CEL-368 - Manual (Page 87)

Typical Instrument frequency range (within +0.5 to -3 dB)
CEL-368 - Type 2:
70-140 range: 9 Hz to 55 kHz,
40-110 range: 9 Hz to 55 kHz,
10-80 range:
9 Hz to 28 kHz.
Lowest frequency for non-linear distortion <1dB:
CEL-268: 5 Hz,
CEL-368: 9 Hz.
Microphone type for CEL-268 - Type 1:
CEL-192 Measurement Microphone (or equivalent),
Half-inch diameter precision capacitor type, 50 mV/Pa,
Microphone capsule screws on to CEL-225/3 Preamplifier.
Free field (F) and random incidence (R) version are available.
Impedance to be substituted for microphone - CEL-268:
18 pF(CEL-216).
Microphone type for CEL-368 Type 2:
CEL-230 Microphone and Preamplifier Unit,
Quarter-inch diameter pre-polarised electret, typically
10 mV/Pa,
Microphone capsule permanently attached to preamplifier.
The microphone meets Type 2 requirements for both free field
and random incidence measurements.
Impedance to be substituted for microphone - CEL-368:
Not possible, use CEL-316 Line Input Adaptor as a dummy
microphone.
CEL-268/368 Handbook Page - 86