There are three main reasons for having instruments calibrated:
- To ensure readings from an instrument are consistent with other measurements.
- To determine the accuracy of the instrument readings.
- To establish the reliability of the instrument i.e. that it can be trusted.
Traceability: Relating your measurements to others
For measurements to be compared they must share a common measurement system.
Uncertainty: How accurate are your measurements?
A measurement with a stated uncertainty can be compared to others
Measurements are traceable when they can be related to a recognised measurement system, through an unbroken chain of comparisons, each with stated uncertainties
Reliability: Can I trust the instrument?
A calibration certificate will be issued only if an instrument is found to be reliable, and will satisfy its intended purpose
Achieving Traceability in your measurements
To make a traceable measurement three elements are required:
- An appropriate and recognised definition of how the quantity should be measured,
- A calibrated measuring instrument, and
- Competent staff who are able to interpret the standard or procedure, and use the instrument.
Traceability is ensured only if these three factors are present in the measurement process