This paper describes the proficiency testing of the seven laboratories, accredited by National Accreditation Board for Testing and Calibration of Laboratories (NABL), India using a Digital Pressure Calibrator (DPC) [Model No. - H540/101, SI. No. - MC808, make-DH-Budenberg, U.K.] as an artifact in the pressure range 70 bar to 700 bar (7 MPa to 70 MPa). The primary objective for organizing this proficiency testing (PT) is to assess the laboratory's technical competence to perform measurements and also fulfilling the requirement of ILAC/APLAC in regards to the compatibility of results submitted by these laboratories. National Physical Laboratory (NPLI), New Delhi, India has the responsibility of coordinating this programme and also acted as a reference laboratory. The stability of the artifact was assessed by measurements made at NPLI before and after the circulation of the artifact. The comparison was carried out at 11 arbitrarily chosen pressure points i.e. 0.7 MPa, 14 MPa, 21 MPa, 28 MPa, 35 MPa, 42 MPa, 49 MPa, 56 MPa, 63 MPa and 70 MPa throughout the entire pressure range. Six measurements were performed at each eleven pressure points, three each in increasing and decreasing orders of pressures, respectively. Laboratories were advised to report the values of various parameters related to the artifact including the temperatures at which the measurements were made. As it was a digital gauge, all participating laboratories were requested to perform the measurement at a temperature sufficiently close to 23°C so that the standard uncertainty of the various coefficient of the artifact do not contribute to the overall measurement uncertainty. Data are analyzed as per ISO/IEC GUM document. The normalized error (En) values are estimated in the entire pressure range. These results are quite encouraging for the manufacturers and calibration laboratories that are facing a new environment after the WTO agreement.
W pracy przedstawiono wyniki testowania (audytu) siedmiu laboratoriów akredytowanych przez Narodowy Komitet Akredytacyjny Laboratoriów w Indiach (NABL) z użyciem cyfrowego kalibratora ciśnienia DH Budenberg UK, jako artefaktu ciśnienia w zakresie 7-70 MPa.