Measuring instruments significantly related to human safety and the appropriateness of commercial dealings, such as various meters and fever thermometers, must be able to make particularly accurate measurements as stipulated by the Measurement Law. Based on the principle of "protection of consumers (safety, protection of life, commercial dealings, certification and protection of assets)," the Measurement Law was established to "contribute to economic development and cultural improvement by determining standards of measure and ensuring appropriate measurement." With its main role being the supply and control of accurate measuring instruments, the Law also assists the development of the social infrastructure, economic growth, and cultural improvement. Measuring instruments that are required to be able to make particularly precise measurements in line with the Law are called "specified measuring instruments." Specified measuring instruments must undergo type approval and verification before they are put into use. Verification, type approval and inspection of verification standards as specified by the Measurement Law as well as mutual recognition of verification to support type approval form the core of legal metrology.
Of the services to which the Measurement Law applies, NMIJ carries out type approval and inspection of verification standards. Also, we conduct tests on measuring instruments and accept test data of other national metrology institutes based on mutual recognition with other countries. These services are jointly handled by the Legal Metrology Technology Section, the Mass Meter Test Technology Section of the Dynamic Measurement Division, the Legal Flow Metrology Section of the Fluid Flow Division of the AIST Tsukuba Center, and the Dissemination Technology Division at the AIST Kansai Center's Ogimachi Site.     [ Dissemination Technology Division ]

   

   

   

Specified measuring instruments are required to pass the appropriate tests to verify that their structures satisfy the technical standards specified by the Measurement Law before these instruments are put into commercial production. Such testing process conducted by the Japanese government (or agencies certified by the government to administrate the tests) is called type approval. The tests include electric noise tests and durability tests as well as various performance tests.
The Tsukuba Center and the Kansai Center's Ogimachi Site jointly offers services for type approval testing and examinations for the instruments listed below:

Various kinds of equipments are necessary to test the performance of measuring instruments for type approval. Typical testing apparatuses include EMC testers and Nonautomatic weighing instruments temperature testers.    

Verification standards are measuring instruments that are used, from the viewpoint of implementation of precise measurement and maintenance of accurate measuring instruments, as standards for inspecting specified measuring instruments at the time of verification, periodic inspections and other relevant opportunities. The inspection of verification standards is a system to check if they satisfy the minimum required performance by verifying the structures and instrumental errors of the standards. This service is carried out jointly by the Tsukuba Center and the Kansai Center's Ogimachi Site depending on a type of reference standard, as shown below. They also carry out the inspection of verification standards for liquid column pressure meters and density hydrometers.

   

Mutual recognition aims at mutual utilization of type approval test data by both parties (two countries or regions) of a bilateral agreement with regard to type approval of measuring instruments. In other words, when Japan and another country sign up a mutual recognition agreement bilaterally, a measuring instrument that is type-approved in one country is also recognized as a certified instrument in the other, thereby eliminating the need for time-consuming dual procedures. Currently Japan has concluded a mutual recognition agreement with Germany, the Netherlands and some other countries. Measurement certificates issued under this system are based on the certification system of the International Organization of Legal Metrology (OIML). NMIJ issues OIML-based certificates for nonautomatic weighing instruments and fuel dispensers for automobiles.