Standards and calibration facilities for reactive gases
Project Description
The objective of this project is evaluating progress in the development and realisation of standards and calibration facilities for reactive gases.
Both Nmi and NPL are working on realisation of facilities for calibration gases for hydrogen sulphide, hydrogen chloride and low NOx.
This project aims to compare the institutes Primary standards gas mixtures to safeguard international comparability and traceability.
The composition range of the gas mixtures :
| H2S | 5 exp -6 _ 20 exp -6 mol/mol |
| NO/NO2 | 0,5 exp -6 _ 100 exp -6 mol/mol |
| HCl | 30 exp -6 _ 300 exp -6 mol/mol |
Final Report 2005-12-01
Since the start of the project (December 1999) a number of cylinders have been compared for both NO and H2S. The results are presented in the following table:
NO in N2
| Cylinder Number | Xanalytical [µmol/mol] | Xgrav [µmol/mol] | (Xgrav.-Xanalytical) [µmol/mol] | U(Xgrav.-Xanalytical) [µmol/mol] |
| NPL1020 | 10.01±0.08 | 9.965±0.05 | -0.045 | 0.094 |
| NPL1021 | 0.986±0.013 | 0.9816±0.010 | -0.0044 | 0.0164 |
| NMi3635 | 0.494±0.010 | 0.5003±0.0075 | 0.0063 | 0.0125 |
| NMi6269 | 10.08±0.10 | 10.01±0.10 | -0.070 | 0.141 |
NMi coded cylinders were prepared by NMi and analysed by NPL;
NPL coded cylinders were prepared by NPL and analysed by NMi.
H2S in N2
| Cylinder Number | Xanalytical [µmol/mol] | Xgrav [µmol/mol] | (Xgrav.-Xanalytical) [µmol/mol] | U(Xgrav.-Xanalytical) [µmol/mol] |
| NMi5154 | 10.03±0.10 | 10.00±0.15 | -0.03 | 0.18 |
| NPLH220 | 10.11±0.10 | 10.19±0.05 | 0.08 | 0.11 |