The NDIR gas sensor can measure the CO2 gas concentration through the
change of the resistance value of the internal thermistor. The product
is packaged in a TO-39 metal socket and has two separate filters: one is
the reference filter and the other is a narrow bandpass filter for the
CO2 gas band. The sensor integrates electronic components such as
thermopile chips and thermistor, with high reliability and high
sensitivity.