CHEMILUMINESCENT GAS ANALYSER WITH A COOLING UNIT FOR MEASURING OXIDES OF NITROGEN

摘要

A gas analyzer (1) for determining the concentration of an oxide of nitrogen in a sample gas comprising- a reaction chamber (38) for chemiluminescent reaction of nitric oxide and ozone, - a gas collector (5) for collecting a sample of gas with an oxide of nitrogen, the gas collector being connected to the reaction chamber, - an ozone provider (54) connected to the reaction chamber for providing ozone to the reaction chamber, - a detector housing (49) containing a light detector optically connected to the reaction chamber (38) for detecting light (59) from the chemiluminescent reaction and for providing a signal representative of the concentration of said oxide of nitrogen, - a detector-temperature control unit with a cooling unit for controlling the temperature of the light detector, - wherein the detector-temperature cooling unit comprises a gas supply (14, 46) connected to a vortex cooler (47), where the cool gas exit of the vortex cooler is connected to a gas inlet (48) of the detector housing (49) for cooling of the light detector.