The Model 1010 is a single channel cross-duct analyser for the measurement of CO. It uses an infrared transmitter to project a beam of light across the duct to a receiver mounted opposite. The light beam is tuned to a specific wavelength where the CO molecules absorb the light energy but there is no interference from water vapour and other gases. Gas filter correlation (GFC) is used to isolate the interference of dust particulates and by using high efficiency air purges the optical surfaces are protected from contamination. The instrument was the first gas analyser to be designed by CODEL and was initially launched in 1982.