Yes, for NDIR gas ANALYZERS, it is advisable to use a reference channel and NORMALIZE the signal of the gas duct via the quotient process on this reference. The optical, MECHANICAL and electronic drift of the overall system is reduced CONSIDERABLY, and the interval between calibrations can be significantly extended. The spectral position of the optical reference should be located as close as possible to the spectral lines of the gases to be measured. A reference channel can be shared for multiple gases, if all absorption bands lie within a spectral window from 3 to 5 µm or from 8 to 12 µm. Without an optical reference channel, a reference can still be done by PERIODICALLY introducing a reference gas into the channel, such as nitrogen.

Yes, for NDIR gas analyzers, it is advisable to use a reference channel and normalize the signal of the gas duct via the quotient process on this reference. The optical, mechanical and electronic drift of the overall system is reduced considerably, and the interval between calibrations can be significantly extended. The spectral position of the optical reference should be located as close as possible to the spectral lines of the gases to be measured. A reference channel can be shared for multiple gases, if all absorption bands lie within a spectral window from 3 to 5 µm or from 8 to 12 µm. Without an optical reference channel, a reference can still be done by periodically introducing a reference gas into the channel, such as nitrogen.