The laboratory is equipped with a standard gas generator that mixes humid and dry air to produce humidity references traceable to international standards through a link to national standards.

Both types of air are generated continuously at a constant flow rate and are constantly monitored for dew/frost point temperature. The generation ranges for dry and humid standard gases extend from -100°C to +20°C dew/frost point at ambient temperature and pressure. These ranges are certified using a five-stage chilled mirror hygrometer, cooled by a water source and calibrated at NPL.

This laboratory issues Gruter & Marchand verification reports or calibration certificates. These references are covered by the CIPM Mutual Recognition Arrangements (CIPM MRA), which ensure the equivalence of national standards between countries and the global recognition of measurement results and calibration certificates.

This laboratory also uses standard gases and mixing benches to perform calibrations for O2/CO/CO2/CH4/SF6/H2/NO… in percentage and PPM.