NIST and NMi have signed a Declaration of Equivalence stating that certain PSM suites are equivalent. In order to proof this equivalency, a comparison program is agreed for CO in nitrogen or synthetic air, CO2 in nitrogen or synthetic air, Ethanol in nitrogen or synthetic air, Oxygen in nitrogen, Propane in nitrogen or synthetic air, NO in nitrogen, SO2 in nitrogen, BTX in nitrogen or synthetic air, natural gas, H2S in nitrogen and VOC’s in nitrogen or synthetic air. Comparisons will be repeated every 3 years to validate consistency.
Results will be reported within EURAMET and NORAMET.
Progress Report 2022-06-08
- 2021: no progress due to unavailability of NIST laboratories; comparison of mercury generators on hold
- 2020: no progress due to Covid 19
Progress Report 2020-02-25
- 2019: comparison on 200 nmol/mol N2O is completed; comparison on 100 ppm NO2 is ongoing.
Progress Report 2019-03-27
- 2018: Measurments have been performed on 200 nmol/mol of N2O in air; measurements have been performed on zero gas (SO2, NO, CO ,CO2) and a seperate mixture of 200 nmol/mol of NO2; The planned NO2 and HCl comparisons have been delayed to 2019
Progress Report 2018-04-12
- 2017: comparison on 5 micromol/mol H2S in N2 finished with an agreement within 0.2% rel.
- 2017: comparison on 5 micromol/mol CO in N2 finished with an agreement within 0.35% rel.
- 2017: comparison on 30 micromol/mol SO2 in N2 finished wit an agreement within 0.5% rel.
- 2017: comparison on 5 micromol/mol CO in synthetic air finished without agreement; instability of the mixture is considered to be the source of the difference; in 2018 more work will be undertaken to reach agreement
- 2018: comparison started on 200 nmol/mol and 1000 nmol/mol of NO in N2
- 2018: comparison started on 200 nmol/mol N2O in air
- 2018: comparisons on 100 micromol/mol of NO2 on N2 and HCl in N2 are planned to start at the end of 2018