THERMAL CONDUCTIVITY GAUGE

摘要

A thermal conductivity gauge comprises a filament (12) in one arm (20) of a Wheatstone bridge circuit, a variable digital potentiometer (28) in a diagonally opposite arm (16) of the bridge circuit, and a controller (30) for adjusting the resistance of the potentiometer to control the bridge voltage (Vo) so that, during use, the temperature of the filament (12) is maintained at or around a predetermined value.