Establishing equivalence of TILSAM and gravimetry-based analytical capabilities (EETGRAC)

Project Description

A comparison on gas standards will be organized between BAM (preparation and GC-based validation), CENAM (preparation and GC-based validation), IPQ (preparation and GC-based validation), DFM (IR-spectrometric analysis), and PTB (IR-spectrometric analysis) to compare preparative (static gravimetry) and analytical (TILSAM/IR-spectroscopy) capabilities on gas standards containing environmentally relevant species, i.e. CO2, CO, N2O, CH4. Details of the project protocol have been laid down in a comparison protocol agreement.
The protocol is available to interested EURAMET labs upon request. The protocol has been agreed by the proposing institutes CENAM, DFM, BAM, and PTB. Changes and amendments in view of other interested institutes are possible. Other parties are welcome to join in this project.

Final Report 2019-03-28

A CO2 standard at 340 µmol/mol in synthetic air gravimetrically prepared by CENAM was analysed at PTB and DFM by means of laser spectrometric amount fraction measurements (TILSAM). At BAM the CO2 standard was analysed by GC. The values were compared and measurements completed. Comparisons on CH4 standards and CO standards could not be completed due to limited capacities at partners. A CO standard was circulated by IPQ, but was only measured by PTB. Laser spectrometric amount fraction measurements were brought to other EMRP projects within EURAMET though.
The project partners agreed with the SCGA of TC-MC to conclude the 1280 project by this, having only a draft A report on CO2 available. On CO2, all partners agreed with the comparison reference value. The reported measurement uncertainties of the laser spectrometric CO2 analysis of PTB and DFM were 4 % and 0.42 % relative at k=2. BAM reported an relative uncertainty of 6 %.

Progress Report 2018-04-12

2013-2015: analysis by all partners of 340 micromol/mol CO2 in synthetic air
2016: draft A report on CO2
2014-2017: analysis by all  partners on 5 micromol/mol CO in N2
2017: analysis of CH4 and N2O cancelled due to time issues
2017: draft A report on CO
2018: final report ready by the summer of 2018

Metrology in Chemistry (MC)
Olav Werhahn, PTB (Germany)
Coordinating Institute
PTB (Germany)
Further Partners