Atmosphere measuring device and flow sensor

摘要

A low-cost and quick-response type gas-density sensing element is free from positioning error of sensing ambient temperature and gas density and can accurately sense the gas flow even if the environmental conditions sharply change. An output voltage V1 proportional to an ambient temperature is obtained by heating a sensing element at low temperature and an output voltage V2 proportional to the ambient temperature and humidity is obtained by heating the sensing element at a high temperature. An output voltage which is proportional to the humidity is obtained by subtracting the voltage value V1 from the voltage value V2.