What is Traceability?

High accuracy in measurement requires calibration of measuring instruments by an accurate standard instrurnent. Traceability is defined as indicating that "the route by which the user' s measuring instrument was calibrated is known and the route can be traced to the national standards."

Activities of NRLM on Traceability

NRLS is conducting research on various measuring standards such as length, mass, time, temperature, flow rate, force, humidity and vicosity as well as related accurate measuring technologies. Results of the research contribute to the general public in various ways, beinlg used as a technological backbone which supports traceabitlity.

Traceability System Regulated by the Measurement Law ot Japan

Traceability System

The traceability systern is legally defined by the Measurement Law. In this system, when calibration is performed, a certificate of calibration with the logo shown in the figure is issued to certify that the instrument is connected to a "calibration chain," NRLM not only provides technological guidance for designated calibratin bodies and traceability study meetings on each quantity, but also attends the Steering Committee on the National Traceability System of the Ministry of International Trade and Industry.

Link to JCSS Home Page

For measuring instruments associated with trade, certification and safety measures for equipment such as weighing instruments, gas meters and taxi meters, legal certification using verification standards which are calibrated by national standards (referred to as specified standards in the Measurement Law) is required. In this system, traceability has been established through verification standards calibrated by NRLM .

International Traceability

NRLM makes efforts to ensure international conformity regarding national standards through international comparisons and participation in international cooperative research regarding national standards for important quantities.

Cooperative Research and Traceability

NRLM is conducting cooperative research aiming at the development of new standardized measuring methods and calibration methods. The cooperative research can be expected to have the same effect as traceability.