The GГ¶nnheimer Ex p purging unit "continuous purging", Model FS870S, controls and monitors the prepurging and operating phases of analyzers with containment systems in Ex zone 1 and 2.
The purging unit redundantly monitors a continuous protective gas stream through the connected analyzer. Any escaping sample gas is then diluted to below the explosive limit (max. purging gas pressure 100 hPa). At the same time, an overpressure is maintained inside the Ex p enclosure compared with the surrounding atmosphere.
If the purging gas flow or internal pressure falls below a specified minimum value, the supply voltage of the pressurized equipment is switched off.