How to distinguish between metrology, calibration, testing and certification

The main difference between calibration and verification Purpose: Calibration - Self-determination of the accuracy of monitoring and measuring devices. It is a bottom-up traceability of quantitative values and evaluation of the error in the displayed value. Verification - mandatory comprehensive assessment of measurement characteristics. Uniformity of measurement values, checking whether they meet the specified requirements. Top-down transfer of quantitative values. Object: calibration - in addition to the mandatory inspection of measuring instruments and measuring devices. Verification - the national compulsory verification: measurement reference; measurement standards; for trade settlement, safety and protection, health care, environmental monitoring of the work of measurement of seven categories **** 59 kinds. Based on: Calibration - calibration specifications or calibration methods, can be used by the state unified provisions, or by the organization's own development. Calibration - by the state authorized measurement department unified development of calibration procedures. Nature: Calibration - not mandatory, voluntary traceability of the organization. Inspection - mandatory, is the legal measurement of the scope of management of law enforcement. Periodicity: Calibration - by the organization according to the use of the need to determine their own, can be regular, irregular or before use. Verification - in accordance with the mandatory verification cycle prescribed by law in China. Mode: Calibration - can be self-calibration, external calibration or combination of self-calibration and external calibration. Inspection - can only be carried out in the prescribed inspection department or qualified organization authorized by law. Content: Calibration - assessment of the error in the display value. Calibration - assessment of the error of the indication value. Conclusion: Calibration - no determination of conformity, only evaluation of the error of the indicated value. Issue a calibration certificate or calibration report. Inspection - according to the range of error of measurement value specified in the inspection regulations, to give a qualified or unqualified judgment. Issue a certificate of conformity. Legal effect: Calibration - calibration conclusions are technical documents without legal effect. Verification - verification conclusions are legally binding documents, as a measuring instrument or measuring device verification of the legal basis.