Method and apparatus for detecting presence and concentration of vapors in gaseous fluids

摘要

A method of determining the concentration of a vapor in a gaseous fluid comprises the steps of passing a sample of the fluid through a channel having a crystal oscillator therein coated with a substance which absorbs the vapor, monitoring the deviation of the frequency of the oscillator from a base-line frequency representative of a fluid sample having a zero concentration of the vapor and converting the frequencydeviation, if any, to a numerical value indicative of the concentration of the vapor in the fluid.