Patent ID: 6888467

Claim:
A method for operating an instrument for detecting a combustible gas comprising a sensor including a heated surface on which the combustible gas reacts to cause a change in an electrical parameter output of the sensor, an electrical power supply for the instrument including a connection for heating the heated surface, a measuring unit for measuring gas concentration based on the output from the sensor, and an output display indicating a presence of combustible gas, comprising the steps of: providing an actuating means for actuating the power supply; providing a feedback link between the measuring unit and the actuating means; supplying timed pulses of electricity from the power supply to the sensor, the pulses being of sufficient duration to enable the gas to react; and determining, with the measuring unit, the sensor output resulting from the reaction of the gas; and further supplying power to the sensor such that: when the change in said sensor output is less than a predetermined threshold value, continuing supplying said timed pulses of power to the sensor, and when the change in said sensor output is at least equal to said threshold value, supplying continuous power to the sensor to enable continuous measurement of said sensor output.