Reference method for measuring releases of mercury from mercury cell chlor-alkali plants: section 2

Section 2: Application

The method is used to determine the rate of mercury emission in the following gas streams:

1. ventilation gases from the cell room,
   
2. hydrogen stream,
   
3. end-box ventilation stream, and
   
4. gases exhausted from retorts used to recover mercury-contaminated waste.

Caution! Hydrogen and air mixtures are explosive, hence extreme caution must be exercised when sampling hydrogen streams. The following precautions are recommended:

1. prior to sampling ensure that all connections in the meter box are tight and leak-free,
   
2. operate only the vacuum pump during the test,
   
3. use only a glass or Teflon probe,
   
4. seal the sample port to minimize leakage of hydrogen from the stack, and
   
5. vent the sample gas al least 3m (10 ft) away from the train.