Labconco Precise Controlled Atmosphere and Basic Glove Boxes 5220131 - Manual (Page 58)

Appendix G: Helium Leak Test Procedure
Product Service 1-800-522-7658 54
Pressure Relief Valve Test Procedure
1. See that pressure relief valve opens when pressures and vacuum
exceed +/- 6" to 10" w.g. Record data. Check that valve reseals
within 2" w.g. of opening pressure and opening vacuum. Pressure
relief valve is standard on Precise Controlled Atmosphere Glove
Boxes.
Other Equipment
1. For a less critical helium leak measurement using a lower cost leak
detector, Labconco recommends using Restek (www.restek.com) or
other instrumentation available from a laboratory supply dealer.