¶ Unique identifier
¶ Standard
ISO/IEC 17025 requires that a calibration certificate must have a number of features and unique identifiers to minimise the possibility of misunderstanding or misuse.
¶ Common practice
In order to enable unambiguous identifiability, a unique identifier is stored on most calibration certificates - in addition to the features required by ISO/IEC 17025.
¶ Vision of the unique identifier in the Digital Calibration Certificate
Analogous to how a website is uniquely identified worldwide by a host name, e.g. www.ptb.de, by specifying a subdomain (www), a domain (ptb) and a top-level domain (de), a unique identification of a digital calibration certificate can also be made.
A unique identification could then be, for example, D-K-99462-01-01.DAKKS_AB.DE. The breakdown is shown in the following figure.
1234 represents an example of an identifier for the calibration certificate that is uniquely assigned in the calibration laboratory. Each country would receive a top-level domain whose server is operated by the respective national quality infrastructure. For example, Germany would receive DE as a top-level domain. Each public institution of the national quality infrastructure and each accredited service provider can have a domain assigned to it. For example, DAkkS could receive DAKKS_AB as its domain name. Finally, any designation could then be made internally as a sub-domain, e.g. D-K-99462-01-01.