Abstract
Proficiency testing (PT) and interlaboratory comparisons (ILC) are basic tools of the external quality assurance in testing and calibration laboratories. Only PT and ILC can provide an objective and independent comprehensive assessment of results of laboratory activities. The PT and ILC play an important role in confirmation of technical competence and reliability of measurement results. The participation in PT and ILC are mandatory for laboratories accredited or applying for accreditation to ISO/IEC 17025:2005. Trying to meet needs and expectations of all stakeholders Laboratory of Density, Viscosity and Spectral Analysis of the Central Office of Measures (GUM) provides interlaboratory comparisons in the field of calibration of breath alcohol analyzers. Series of comparisons were conducted according to the ISO/IEC 17043:2010 standard in the period from December 2014 up to October 2015. Ten laboratories, which were accredited or in process of preparation to accreditation by Polish Centre for Accreditation, participated in these comparisons. This paper presents general rules and a course of the comparisons, the results of calibration by participants of the Intox II EC/IR analyzer in four test points: 0,10 mg/l, 0,25 mg/l, 0,41 mg/l, 1,52 mg/l in comparisons, laboratory performance evaluation according to the accepted criteria, interpretation of the results of measurements of density of liquid ethanol standards and the correlation analysis of the calibration results in four measurement points.
