TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 CONT

A simple arrangement of two cavities in series showed the feasibility of detecting traces of one gas in another. A klystron was used to generate microwave power which was fed through a wave guide to a transmission-type cavity. Another cavity was mounted in series with and tuned to the same frequency as the first; both cavities were identical except that the second had a gas inlet and outlet ports. From this measuring cell, its microwave energy was sent to a crystal detector. By frequency-modulating the klystron with a 50-cps sine wave voltage on the repeller, a burst of energy passes to the detector each time the generator frequency equals that of the cavities. The detector current is amplified and measured with an oscilloscope. At the beginning of the run, the two cavities are filled with the nitrogen carrier gas and, if the composition in one of the cavities is changed, its electrical size will change... causing a decrease of current from the detector.  1, record 1, English, - crystal%20detector

Record 1,  Textual support,  French

Record 1,  Textual support,  Spanish