How do you verify calibration?

Calibration is an essential process in various industries to ensure the accuracy and reliability of measuring instruments and equipment. It involves comparing the values obtained from a device under test with a known standard. However, how do we verify that the calibration itself is accurate? In this article, we will delve into the methods and techniques used to verify calibration.

1. Interlaboratory Comparison

One way to verify calibration is through interlaboratory comparison. This method involves sending the same device or sample to multiple accredited laboratories for calibration. The results obtained from each laboratory are then compared to check for consistency and agreement. If the measurements are within an acceptable range of each other, it gives confidence in the accuracy of the calibration.

2. Control Charts

Control charts are another useful tool for verifying calibration. These charts track the performance of a measurement system over time by plotting individual measurements against control limits. Any deviation or trend observed outside these control limits indicates a potential calibration issue. By regularly monitoring control charts, deviations can be detected early, leading to corrective actions to maintain accuracy.

3. Certified Reference Materials

Certified reference materials (CRMs) are specific substances with known properties that are used to validate measurements. By comparing the values obtained from a device under test with those provided by the CRM, the accuracy and reliability of the calibration can be verified. CRMs are particularly valuable when calibrating complex systems or instruments that require traceability to recognized standards.

Conclusion

Verifying calibration is crucial to ensure the accuracy and reliability of measurements. Through interlaboratory comparison, control charts, and certified reference materials, the calibration can be validated. By implementing these verification methods, organizations can have confidence in the accuracy of their measurement systems, which is vital for quality control and decision-making processes.