Patent ID: 6156578
Filing Date: 2000-12-05
Classification: G01G,G01N,Y10T

Abstract:
A system for sensing concentration of a gas component in a gas stream, wherein the gas component is reversibly reactive with hydroxyl functionality, said system comprising:(a) a device for sensing concentration of a gas component in a gas stream, said device comprising:(i) a quartz crystal microbalance including a quartz crystal with a surface functionalized with hydroxyl functionality which reversibly reacts with the gas component to yield a surface-bound reaction product that (1) effects a change in the oscillation frequency of the quartz crystal and (2) subsequent to reaction is regenerable in the presence of water vapor to re-establish the hydroxyl functionality on said surface; and(ii) means for sensing the oscillation frequency of the quartz crystal and generating an output correlative of the concentration of the gas component in the gas stream(b) a source of water vapor arranged in fluid communication with the quartz crystal microbalance for re-establishing the hydroxyl functionality on the surface of the quartz crystal microbalance.