Method of increasing the measurement accuracy of a gas analyser

摘要

80% of the applications of gas analysers are in the field of process automation and environmental protection and require precise determination of concentrations of gas components in gas mixtures in the ppm range, accompanied by appropriate measurement accuracy and high reproducibility of the measurements. This can be achieved by calibrating the measuring system and operation checks at closely spaced intervals of time. In contrast to the known methods, in the proposed method the light attenuation is treated not solely as a function of the partial pressure of the light-attenuating gas component, but allowance is also made for other effects which govern the light attenuation, such as gas temperature, the concentrations of various gas components, the total pressure of the gas mixture, and the gas components which alter the measured signal as a result of absorption. The advantages achieved with the proposed method are that a substantial expansion of the possible applications of gas analysers is made possible by relatively simple measures and that traces of a gas can be measured with increasing accuracy and improved reproducibility of the values even in the ppm range.