Euramet comparison for ethanol in nitrogen: EURAMET.QM-K4.1

Ethanol measurements in human breath are important for the implementation of legal metrology related to the driving under influence legislation. Measurements are typically performed to calibrate breath testers in accordance with OIML Recommendation R126:1998 (evidential breath analysers) in the range from 50 mu mol/mol up to 800 mu mol/mol ethanol in nitrogen or air. Six national metrology institutes participated. The KCRV is based on the gravimetric preparation. Its uncertainty appreciates effects from adsorption of ethanol to the cylinder wall, weighing, and purity analysis. Only VNIIM shows a result which is inconsistent with the KCRV. Both VNIIM and CEM show a result that deviates more than 1% from the reference value. This Euramet comparison is linked to CCQM-K4; as NPL and VSL participated in both comparisons, this can provide a link between the two comparisons.