Certification: A third party gives a written guarantee (certificate of conformity) that a product, process or service meets the specified requirements according to procedures. For example, quality system certification is a type of certification.

Accreditation: A formal recognition by an authority that an organization or individual has the ability to perform a specific task.

Note: Accreditation itself does not give the laboratory the qualification to approve any specific product, but when the approval and certification bodies decide whether to accept the data provided by the laboratory related to their business, accreditation may be related to these organizations.

Laboratory accreditation: A formal recognition of whether the calibration/testing laboratory has the ability to perform a specified type of calibration/testing.

Calibration and measurement capability: The highest calibration and measurement level usually provided to users, which is expressed in an expanded uncertainty with a confidence level of 95%. Sometimes called the best measurement capability.

Calibration: A set of operations under specified conditions to determine the relationship between the value indicated by the measuring instrument (or measurement system), or the value represented by the physical measuring tool (or reference material), and the corresponding value reproduced by the measurement standard.

Note: 1. The calibration result can give the measured value and determine the correction value of the indicated value.

2. Calibration can also determine other metrological characteristics, such as the effects of influencing quantities.

3. The calibration results can be recorded in a calibration certificate or calibration report.

4. Physical measuring instruments refer to instruments that reproduce or provide one or more known values of a certain quantity in a fixed form when used. Such as gauge blocks, weights, standard resistors, standard signal generators, reference materials.

Detection (testing, experiment): For a given product, a technical operation consisting of determining one or more characteristics, processing or services in accordance with prescribed procedures.

Measurement: A set of operations for the purpose of determining the value of a quantity.

Metrology: An activity to achieve unified units and accurate and reliable values of quantities.

Verification: A procedure to find out and confirm whether a measuring instrument meets statutory requirements, which includes inspection, marking and (or) issuing a verification certificate