Thermal conductivity detector circuit

摘要

There is disclosed a circuit which supplements a bridge-type detector circuit in order to minimize non-linearities resulting in measurements of thermal conductivity by such type bridges. An auxiliary voltage source is described which has an adjustable output voltage which is servoed to follow the output voltage of a differential amplifier which is connected to the output of the bridge. When the bridge is balanced at the desired operating temperature, the auxiliary supply is switched in and this voltage now controls the current supplied to the bridge instead of the differential amplifier output voltage thus eliminating the cause of the non-linearities at the point of measurement.