Helium Permeation Leak testing from rugged teflon and glass permeation elements. Listed below are a few of our many possible combinations of helium permeation leak testing. LACO's Calmaster line of calibrated gas leak standards including helium leak testing are available in a broad range of gases and leak rates. All leak standards come calibrated NIST traceable by our A2LA accredited calibration lab (complies with ISO Guide 25 and ANSI/NCSL Z540-1-1004). Applications are: Calibration of helium mass spectrometer leak detectors, „h Calibration of sniffing gas leak detectors - all gases including refrigerants, Calibration of residual gas analyzers, Production leak detection verification, Replacement internal leaks for helium leak detectors, Calibration of pressure decay leak testers.