Inspection is the determination and examination of the conformity of measuring instruments with legal requirements to meet specific technical standards or not, the results are determined by the state inspection agency as passed or not. Inspection is mandatory for measuring instruments included in the "List of mandatory inspection equipment" according to Circular No. 23/2013/TT-BKHCN dated September 26, 2013 of the Ministry of Science and Technology. Inspection of measuring instruments is performed by measurement inspectors in accordance with inspection procedures. After inspection, measuring equipment that meets the requirements will be affixed with an inspection stamp or issued an inspection certificate by the State management agency of measurement or an authorized State inspection facility and is legally valid nationwide. Calibration of measuring instruments is the re-establishment of a correlation between measurement and measuring instruments. Calibration is not mandatory. Based on the calibration results, customers can decide whether or not to use the equipment.

The technical nature of calibration and verification is the same: it is the comparison of measuring instruments with standards to evaluate their errors and other technical and metrological characteristics. The difference is that verification is required by law, mandatory to apply while calibration is voluntary.

Certification is the assessment and confirmation of the conformity of products, production processes, and service provision with applicable published standards (called conformity certification) or with technical regulations (called conformity certification).

(According to the Law on Product and Goods Quality No. 05/2007/QH12 dated November 21, 2007)

State inspection of product and goods quality (hereinafter referred to as product and goods quality inspection) is the act of a state agency reviewing and re-evaluating the quality of products, goods, production processes, and service provision that have been assessed by conformity assessment organizations or have been subject to other quality management measures by production and business organizations and individuals.

(According to the Law on Product and Goods Quality No. 05/2007/QH12 dated November 21, 2007)