Method of determining the component of a gas in a gas sample

摘要

The invention is directed to a method for determining the portion of a gaseous or vaporous component in a gas mixture utilizing a detecting substance which can enter into a chemical reaction with the component to produce a coloration of the detecting substance and utilizing a device for evaluating the coloration. The method includes the steps of: passing the gas mixture at a constant volume flow through a channel containing the detecting substance; detecting a reflectance signal I(t) within a defined spatially fixed length segment of the channel; determining a slope DELTA I/ DELTA t at the start of the chemical reaction during a time interval DELTA t in which the detecting substance is present in excess; determining a saturation reflectance signal I100% toward the end of the chemical reaction which corresponds to an almost complete chemical conversion of the detecting substance within the length segment; and, determining a normalized slope in correspondence to the formal relationship: DELTA I/(I100%* DELTA t), which is proportional to the portion of the gaseous or vaporous component.