Intercomparison exercise of high pressure gas flow test facilities within GERG

Ten of the main European gas Companies decided to carry out the second intercomparison exercise of high pressure test facilities within GERG (Groupe Européen de Recherches Gazières). The survey has compared the performances of 8 high pressure gas flow laboratories in the period autumn 1998–autumn 1999.

The aim was to check to what extent results obtained at the various laboratories are comparable and to reveal possible ways of improving the performances. Tests have been carried out using three transfer standard packages of three different diameters. The considered performance parameters have been: (1) agreement of results between laboratories, (2) short term stability and (3) day to day reproducibility of the reference flow.

The following main conclusions have been drawn:

• The majority of the laboratories involved in the intercomparison produced very accurate results. Despite the involvement of five independent traceability chains, 92.5% of the test results are within a band of ±0.25%.

• For most facilities the short term fluctuations are of the order of ±0.1%. Individual facilities may perform even better.

• This exercise allowed us to confirm the good results of the previous campaign and to identify some items to improve future intercomparisons.

Author Keywords: Intercomparison; Transfer standard package; Laboratory; Meter