| 摘要 |
PROBLEM TO BE SOLVED: To provide a signal processing circuit, a signal processing method, and a gas sensor, allowing the concentration of detected gas to be directly displayed from a measurement value and something like that. SOLUTION: A light signal showing a state where no detected gas exists is photoelectrically converted by a photodiode 6 to acquire an input signal. A reference voltage of a reference voltage source 23 is previously adjusted by a variable resistor VR according to the input signal. In concentration measurement on the detected gas, the reference voltage and an input signal from the photodiode 6 are differentially amplified by an operational amplifier 24, the input signal is acquired by photoelectrically converting a light signal showing a state where the detected gas exists. A differential output of the operational amplifier 24 corresponds to the attenuation factor of the light signal, that is, the concentration of the detected gas. COPYRIGHT: (C)2009,JPO&INPIT |
