1. Establish, maintain and certify the traceability of measuring equipment;

2. Correct the deviation and uncertainty of the device measurement value from the reference value;

3. Improve the reliability of the equipment uncertainty;

4. Determine whether the performance of the equipment has changed.

5. Which equipment needs to be calibrated?

If the accuracy or uncertainty of the measurement affects the validity of the reported results or the metrological traceability of the reported results, the instrument should be calibrated.