CONCENTRATION RATIO CALCULATION METHOD FOR TWO-COMPONENT GAS AND CONCENTRATION CALCULATION METHOD FOR GAS TO BE DETECTED

ObjectA method that highly accurately obtains a concentration of a detection target gas using two gas sensor elements is provided. A method that obtains a concentration ratio of a two component gas using one gas sensor element is also provided.Solution meansThe method for calculating concentration ratio includes: (a) heating a gas sensor element to a temperature at which both of two gas components introduced in a gas sensor element react, and maintaining the temperature for a predetermined period to measure an electrical resistance value of the gas sensor element; (b) heating the gas sensor element to a temperature at which only any of the two gas components reacts, and maintaining the temperature for a predetermined period to measure an electrical resistance value of the gas sensor element; and (c) calculating a concentration ratio of the two gas components based on a combination of the electrical resistance value in (a) and the electrical resistance value in (b).