Legal metrology
Legal metrology is the part of metrology relating to activities which result from statutory requirements and concern measurement, units of measurement, measuring instruments and methods of measurement and which are performed by competent bodies.

Terms
Some major terms related to legal metrology are:

• type or pattern evaluation
• type approval
• verification of a measuring instrument
• verification mark
• rejection mark
• sealing mark

Complete list
A complete list of terms from legal metrology is issued by OIML: the International Vocabulary of Terms in Legal Metrology, in short VIML.

type investigation
Investigation of a type (model) of a measuring instrument executed to determine whether the type (model) can be approved of has to be rejected.

type- or model approval
Decision that confirms whether a type (model) of a measuring instrument meets the legal requirements.

Verification of a measuring instrument 
A procedure (other than type approval) which means the investigation, marking and or the issuing of a verification certificate, with which can be determined and confirmed that the measuring instrument meets the legal requirements. 

Verification mark
Mark attached to a measuring instrument as an indication that the measuring instrument passed the verification with sufficient result.

Rejection mark
Mark attached in a noticable manner on a measuring instrument, indicating that the measuring instrument does not meet the legal requirements. Possible verification marks that were attached prior are no longer valid.

Sealing
Mark that protects the measuring instrument against forbidden modifications, removal of parts etc.