MODEL 149 DUAL CHANNEL CHARGE AMPLIFIER
Features
Description
The Model 149 is an economical 2-channel-
per-module charge amplifier
that plugs into Encore's 19" GPSC instrumentation
rack, which accommodates up to eight modules (16 channels). An AC
power supply is built into the rack, and provides the required unregulated
DC voltages to operate the modules. A continuously adjustable 10-turn
locking dial selects accelerometer sensitivity from 1 to 110pC/g. Outputs
are AC acceleration, and RMS/DC displacement. A front panel pushbutton
or remote CAL command applies a 1000pC 350Hz calibration signal to both
channels simultaneously.

Specifications
Input signal: Charge output from accelerometer
Input sensitivity: Front panel locking dial, adjustable from 1 to 11pC/g or 10 to 110pC/g, with internal 1 or 10 gain select jumper
Acceleration gain: Front panel switch selects 10mV/g or 100mV/g
Acceleration frequency response: 5Hz to 15kHz (factory adjustable)
Integration: Two stages convert acceleration to displacement, with unity gain frequency factory set at 350Hz
Displacement gain: Front panel switch selects 10mV/mil or 100mV/mil
Displacement frequency response: 15Hz to 15kHz, adjustable with components on plugin header
Acceleration output: ±10V max, 10mA peak load
DC output: DC voltage equal to RMS value of either acceleration or displacement signal, selected by front panel switch; +7VDC max
Calibration: 500pC (peak) at 350Hz sinewave, applied to both channels simultaneously when front panel pushbutton is pressed, or on rack CAL command
Maximum signal input: 12000pC peak, up to 2kHz
Power: Unregulated ±24V from rack-mounted supply
Mechanical: 19"W x 5.25"H x 9"D, 8 module (16 channel) rack adapter, Model 4015-113