Quality assurance system of transformer diagnostics laboratories

Assurance of the quality system of laboratories for transformer physical-chemical diagnostics necessitates the implementation of particular activities so as to provide for an appropriate diagnosis of an observed transformer. Adoption of the quality system assures the constant and adequate quality of most of the laboratory services. The quality system is formally approved after the laboratory has been granted accreditation. The paper shows vital elements that a laboratory applying for the testing laboratory accreditation has to define and document in accordance with the requirements of the standard ISO 9002:1994 Quality systems-Model for quality assurance in production, installation and servicing, and the recent standard ISO/IEC 17025:1999 General requirements for the competence of testing and calibration laboratories. The paper further defines phases of the working process ensuring the quality operation of the transformer diagnostics laboratory, not just a standard oil testing laboratory. The presented quality system has been adopted by the Institutes Chemistry Department and was internationally certified in March 2001 by the Dutch Accreditation Council RvA operating under the name STERLAB. The assessment of the Institutes Chemistry Department performed in October 2000 by RvA, was their first assessment conducted in accordance with the ISO/IEC 17025:1999 standard.