Calibrator comprises state variable sine wave generator driving precision 3 digit attenuator.
Selector switch routes attenuator output via the 04 housing backplane to a maximum 10 x 04 charge amplifier CAL input terminals.
Charge amplifiers may be calibrated individually or simultaneously.
Additional controls allow choice of rms/pk. sine output, and operation mode (ON/OFF/ MOM.ON toggle).
MOM.ON reverts to OFF on release of finger pressure and therefore eliminates inadvertent activation. Output of the CU/04 is a stable, low distortion 70.5Hz sine wave adjustable over the range 1-999mV (pC) in 1mV (pC) increments.
Conversion to charge is internal to the charge amplifier(s) under calibration via the 1nF capacitor coupling the CAL input terminal to the transducer signal input.

OPERATION
The pC attenuator may reflect a specific channel g x transducer sensitivity (pC/g) or simply an arbitrary pC level for multi-channel calibration.
Calibration signals will be superimposed upon any active channel data.

1g pk. sine @ 70.5Hz is equivalent to 22mm/sec pk. sine and 0.1mm pk./pk. sine.
Thus velocity and displacement data may be validated.

The attenuator is driven by a 1V pk/rms signal, trimmable via the CU/04 front panel, and available at the backplane for routing to a level meter.