Abstract:
In 1993, the measurement law was revised and enacted in Japan. The old law had provided only the use of legal metrology units and the approval and verification systems for measuring equipment. The new one has added the provision of a traceability system to match the needs for a high accuracy measurement technique and international mutual recognition. In the Electrotechnical Laboratory (ETL), the national standard of sound-pressure level has been established and maintained in an audible frequency range. The type approval test and verification of sound level meters have been carried out in the Japan Quality Assurance Organization (JQA). Now, in conformity with the law, ETL has started to construct the new traceability system for the acoustical standards in cooperation with JQA. An outline, is made of the traceability system in Japan and of the newly constructed pressure calibration systems for laboratory standard microphones.