“ISO/IEC 17025” - The Objective Proof
At the NTK COX Calibration Center to which we belong, it has become a given that customers demand guaranteed reliability in calibration testing and results. In other words, it is not enough just to say that ‘we perform high-quality calibrations’; we need ‘objective proof’. NTK International is recognized by an authoritative certifying body (the National Institute of Technology and Evaluation) for having quality management systems and calibration technology that meets the international standard “ISO/IEC 17025”.
Also known as the ‘Calibration Certificate’, the ISO/IEC 17025 is a global standard on which to base judgements about whether or not the results of a test or calibration are credible. The fact that we have acquired this certification is our ‘objective proof’.
Calibration Certainty born from ‘Uncertainty’
One of the defining points of the ISO/IEC 17025 is traceability. For example, say a customer asked us to calibrate an aircraft flowmeter. As calibration is ‘comparing measurement values of a flowmeter with another standard measuring device and adjusting accordingly’, the standard flowmeter has to be of higher-quality than the customer’s. And that standard device has to be calibrated with a device of even higher quality. By tracing each of these flowmeters, we eventually find our way back to the ‘national standard for measurement’. The fact that we can trace this chain of calibrations leading to the national standard shows traceability.
‘Uncertainty’ is one of the important factors when it comes to calibration. Uncertainty refers to a scale that quantifies the differences in measured values. It is an index that shows ‘how uncertain a value is’ based on the fact that ‘finding the real value is nearly impossible’. A measurement in which the level of ‘uncertainty’ is unclear is judged to be missing the basis of traceability. ‘Uncertainty’ needs to be recorded on the calibration certificate for it to meet the requirements of ISO/IEC 17025.
In order to calculate ‘uncertainty’, we need to have a quantitative and complete understanding of all the factors that could affect the outcome of a calibration. These factors can include things such as temperature, viscosity and duplicability, but to understand these factors, we needed to repeat large-scale experiments and analyses. This persistent work helped us to gain a deeper understanding of the ‘calibrations’ we perform. By understanding and endeavoring to reduce ‘uncertainty’, we hope to provide more ‘certain’ calibrations.
Our Future and What We Care About
Finally, I would like to discuss the advantages of performing calibrations in our domestic NTK COX Calibration Center. The country we mainly import products such as flowmeters from is America, but our customers are almost all in Japan. If we asked COX Instruments to perform calibrations, we would need extra time to allow for translation and interpretation. It would also take time to send the products over. We may run into trouble with delivery services overseas too, different from Japan. And above all, it would become difficult to meet our customers’ specific needs. These disadvantages are the reason we keep calibration within the country borders.
It is thought that public demand from the aerospace industry will increase and the need for high-quality flowmeters for engine maintenance will grow. With this in mind, we should be able to contribute to the development and safety of the aerospace industries if we continue to improve the precision of our calibrations. There is great responsibility in that one small miss could lead to a large accident, so our staff will continue to improve their technical skills and adapt to the evolution of the machinery we use so they can demonstrate their expertise as professionals.