What is the conceptual difference between the verification and calibration of measuring instruments?

Checking of measuring instruments: the process of ascertaining and confirming whether a measuring instrument meets the legal requirements, which includes checking, marking and/or issuing a certificate of checking.

Calibration: a set of operations to determine, under specified conditions, the relationship between the values indicated by a measuring instrument or measuring system, or the values represented by a physical gauge or reference material, and the corresponding values reproduced by a standard.