Edutorials
Learn more about calibrations.The field of testing, research and calibration is very broad. It's easy to get lost in technical jargon. Kiwa Dare publishes an edutorial about calibrations. Written in plain language!
How do I determine the right calibration inverval?
Save costs with the right calibration interval -
Determining a suitable calibration interval can be quite a difficult task.
"What calibration interval should I use for this instrument" or "We have extended the calibration interval because we have less budget, is this allowed?" are questions that are frequently asked. The answer to these questions depends on various factors and must therefore be determined individually on the basis of the following points:
Allowed deviation (tolerance)
- Application of the measuring instruments
- Stability of the measuring instruments
- Quality requirements
- Environmental factors (climate controlled lab or service bus)
- The risk to be taken
Calibration Interval
With new measuring instruments, it is generally possible to start with the calibration interval specified in the manual of the instrument. If the manual does not prescribe an interval, you can start with the standard calibration interval of 12 months. After a number of calibrations, the interval can be gradually extended or shortened, depending on the deviation and stability of the measuring instrument.
Risk
However, with the lengthening of the interval, the risk also increases.
For example, if a measuring instrument proves to be out of specification after 24 months, it may be necessary to recall and retest all tested products. At a calibration interval of 12 months, the tester might have been just within specification. In any case, the number of products to be recalled would have been significantly lower. An unrealistically long calibration interval will therefore lead to higher costs!
Consideration
Determining the correct calibration interval is therefore a trade-off between costs on the one hand and the risk of incorrect measurements on the other. This risk will differ per case and depends on the application of the relevant measuring instrument. What are the consequences (costs) of incorrect measurement results. These can be products that are wrongly approved on the one hand or wrongly rejected on the other hand. This also plays a role in the development phase. If, based on incorrect measurement results, it is decided to further improve the product (thus unnecessarily), this will cost time and material for a redesign.
Cost
Unfortunately, calibration is often wrongly seen as a cost item or difficult. As we can see before, you can avoid many problems and the associated costs. Unfortunately, this often only becomes clear when a manufacturer or test house is confronted with a claim for damages or has to recall products.
Calibration Plan
Calibrating according to a well thought-out calibration plan is an investment in quality and customer satisfaction. In addition, by only calibrating the necessary instruments and choosing the correct calibration interval for the various measuring instruments, you can in many cases actually reduce these costs!