Non-Dispersive Infrared (NDIR) Dual Trace Gas Analyzer and Method for Determining a Concentration of a Measurement Gas Component in a Gas Mixture by the Gas Analyzer

摘要

A modulator wheel of a gas analyzer which contains an opening in the shadowing part thereof, where the opening generates in the measurement signal of the gas analyzer, in addition to a signal component at a modulation frequency generated by alternating shadowing and passing-through of the radiation, a further signal component having twice the modulation frequency that is used for detecting changes to the infrared radiation source or detector arrangement due to contamination, aging, or temperature, and compensating for the effects thereof on the measurement result.