Patent ID: 6630833
Filing Date: 2003-10-07
Classification: G01N,G01R

Abstract:
A system for detecting the presence of a desired chemical, said system comprising:an RF oscillator, which includes a gain element which has substantial gain at frequencies greater than 100 MHz; a feedback path, coupling the output of said gain element to the input thereof, said feedback path including a tunable resonant circuit; an electromagnetic propagation structure which is RF-coupled to said oscillator, said propagation structure comprising: a first metallic mesh enclosing said conductor; and a first adsorbent media contained between said central conductor and said metallic mesh, said first adsorbent media selectively adsorbing said desired chemical; wherein electromagnetic wave propagation is electrically loaded by said desired chemical and circuitry connected to monitor the frequency of said oscillator to ascertain changes in the concentration of said chemical.