NIM represents China in internationa measurement comparison. The data is stored in the database of BIPM and opened to the public (www.bipm.org). The standard calibration device for calibrating high precision coordinate measuring machines developed by its subordinate research department of Thread / Coordinate Measuring Technology can be used for calibrating length standard artifacts such as step gauges, sphere plates, sphere beams and ball bars, etc.. Their calibrating accuracy has reached the international advanced level.

    The calibration report of step gauge issued by NIM can be assured worldwide.
(The following content is extracted from the official website of NIM)

    Founded in 1955, the National Institute of Metrology (NIM) is China’s national metrological institute and technical center for legal metrology, affiliated with the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ). Same as other NMIs,NIM is tasked with establishing, maintaining and improving national measurement standards and conducting research on relevant technologies to achieve more precise measurements.
    Up until now, NIM has established 124 national primary standards and 220 national standards. By disseminating these standards to lower levels of standards and customers and participating in international comparisons, NIM provides essential insurance for the accuracy and reliability of quantity values within China and their international consistency.
    Thread / Coordinate Measuring Technology affiliated with Division of Metrology in Length and Precision Engineering of NIM is tasked with the research, establishment and improvement of the method,technology, equipment and national measurement standards of thread and coordinate measuring machines.
    The lab Thread / Coordinate Measuring Technology has made a research of calibration technology of Coordinate Measuring Machines for a long time, participated in or presided over the national standard of coordinate measuring machines and the national standard of calibration .
 The lab Thread / Coordinate Measuring Technology has advanced calibration instruments and experienced metrologists. They developed a standard calibration device for calibrating high precision coordinate measuring machines . This device can be used for calibrating length standard artifacts such as step gauges, sphere plates, sphere beams and ball bars, etc.. Their calibrating accuracy has reached the international advanced level.
    They have high precision coordinate measuring machines which enable them to offer the service of calibrating standards of different shapes or checking high precision workpieces.
    Standard of calibration device for calibrating coordinate measuring machines
    They execute JJF 1064-2004 "Coordinate Measuring Machine" calibration standard and offer the service of calibrating the probing error, indication error of measurement, four- axis error of CMM with rotary table, scanning probing error of CMM with scanning and probing, multiple-Stylus Probing System Location Error of CMM, etc..
Based on years of research, they can also offer the service of calibrating the probing error and indication error of CMM with optical probe.
    Achievements in scientific research:
    Traceability Technology of CMMs

    Standard calibration device which can calibrate length standards of complex shapes, such as step gauges, sphere plates, sphere beams and ball bars, etc.. Their uncertainty of calibrating ball bar can reach:
      
       In international comparison, their measurement uncertainty was verified (Lab 13 in Figure 1)

Figure 1. Internationa comparison result of ball bar BIPM CCL k6