In order to improve the problem of precision of the circuit catalytic combustible LNG sensor and the working life and stability of gas sensor
a new constant temperature detecting circuit is developed.Theoretical analysis and experimental research of self-calibration technique of zero drift and sensitivity are done based on this circuit.Experimental data show this technique can be used to solve the zero drift and sensitivity attennation of the sensor
and scientific basis is provided for the design of combustible gas detector with self-calibration technique.