EN ISO/IEC 17 025: Measurement traceability

All equipment used for tests and/or calibrations, including equipment for subsidiary measurements having a significant effect on the accuracy or validity of the result of the test, calibration or sampling shall be calibrated before being put into service. The laboratory shall have an established programme and procedure for the calibration of its equipment.

Such a programme should include a system for selecting, using, calibrating, checking, controlling and maintaining measurement standards used as measurements standards, and measuring abs test equipment to perform tests and calibrations.

The laboratory shall have a programme and procedure for the calibration of its reference standards. Reference standards shall be calibrated by a body that can provide traceability.

Reference materials shall, whenever possible, be traceable to SI units of measurement, or to certified reference materials. Internal reference materials shall be checked as far as is technically and economically practicable.