Gas concentration monitor - with side stream pumper in variable volume and circulated through semiconductor measuring module

摘要

The concn. of toxic or other gases in a working place is monitored both as regards instantaneous readings and average readings over a period of time. A sample stream is continuously extracted and passed to an instantaneous analyser and to a vessel with a variable volume. The contents of the vessel are constantly circulated and a semiconductor measuring module determines the concn. averaged over a set time, and operates an alarm if a threshold is exceeded. This provides a continuous supervision and eliminates integration errors. In case of an alarm, the sample is still available in the vessel for a detailed analysis.