ZERO POINT CORRECTING CIRCUIT

摘要

PURPOSE:To eliminate the error of the zero point in the measuring state by providing a means which corrects the deviation of the zero point between forcibly generated standard state and the actual measuring state. CONSTITUTION:A variable resistance VR2 is provided as the correcting means, and a switch S1 is switched to the side of a contact (a) at the time of turning off a heater and is switched to the side of a contact (b) at the time of turning on the heater. Since a voltage VA generated in the variable resistance VR2 at the time of turning off the heater is applied to the contact (a) to cancel the difference of offset between turning-off and turning-on of the heater, the value of the output signal of an amplifier indicates zero when the actual flow rate is zero.