Aggressive gas monitor AGM

In many cases the process gas te be examined is so aggressive that the cathode would survive for only a short period of time. The AGM uses the property of laminar flow by way of which there is no reverse flow of any kind. Controlled with a separate AGM valve, a part of the working gas fed te the processes is introduced as purging gas , ahead of the pressure converter, to the TRANSPECTOR this sets up a flow toward the vacuum chamber. Thus process gas can reach the TRANSPECTOR only with the AGM valve closed. When the valve is open the TRANSPECTOR sees only pure working gas. Fig. 4.9 shows the AGM principle. 

Impact chamber - Cathode chamber Exit diaphragm  

Residual gas (valve closed) 10 mbar total total, including 1% by mass 28 10 mbar 

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