Signal value determination and measurement uncertainty of infrared gas sensors

Measurement errors of infrared gas sensors depend strongly on the method chosen for signal value determination. Existing methods for the determination of the concentration-dependent signal value of the infrared detector AC output voltage are very sensitive to noise and to drifts of the mean value of the detector voltage. Compared with conventional methods the suggested novel method using a-priori knowledge about the signal shows very good suppression of drift measurement errors. A further advantage is the online calculation of the measurement quality factors.