These instruments accept inputs from various analog voltage sources, including DC-to-DC LVDT's, potentiometer-type sensors, Hall-Effect devices, photocells, current shunts, and the outputs of other instrument systems with various grounding configurations and voltage/impedance levels.
The Model 3163 Analog Input Conditioner is the basic "Form 1" instrument.
The Model 3263 Analog Input Conditioner / Indicator is the "Form 2" instrument, providing vivid front-panel digital indication of measured values, scalable in desired engineering units.