Importance of Calibration Intervals
When you buy your measurement equipment from a reputable supplier, that device should be calibrated per the manufacturer’s recommendations and the standards set by your State law. At the time the equipment is set up for your use, you should be provided with proof, usually in the form of a Certificate of Calibration, which insures that the device is measuring accurately. Typically, the device should be tested and calibrated before usage. That is the only way you will know for sure that the measurement results are accurate.
Measurement devices are used in almost all manufacturing, testing and processing applications. The integrity of your final product is dependent upon the accuracy of your measuring device, be it a scale, balance, gage block, temperature probe, flow meter, etc. Deviations from the specifications for product weight, size, thickness, etc. could be very costly, resulting in waste and potential liability. Even though your device is professionally calibrated when you start to use it, we all know that it won’t stay that way!
Measurement devices are tools, some mechanical, some electronic, some static. They are subject to wear and tear and too many adverse environmental factors. As devices are used, they wear. Most devices have moving parts which, with usage, will shift or bend or move out of place. From the smallest caliper to a 140’ truck scale, usage will impact the accuracy of your measurement results. Exposure to different environmental factors will also affect results. Cold, heat, operator misuse, bumps, accidents or simply moving the device will often challenge calibration. Rest assured that the higher the usage of the device or the more hostile the environment, the more likely the calibration will change. Those changes will directly impact the integrity of the product or test result you are providing to your customer.
Similar to your car or your home furnace, your measurement devices should be on a regular calibration/ maintenance schedule. Your supplier should be able to recommend the interval schedule which you most likely also see discussed in the users’ manual for the device. While manufacturer’s recommendations are important, you should discuss the specific use of the device to insure that it stays in calibration. Another factor which must be considered is the requirements of your quality system and those of your customers. Lastly, check the manufacturer’s warranty. Often, the validity of the warranty requires regularly scheduled calibration and maintenance. This information should be described by your vendor.
How do you choose a calibration services vendor? There are several very important factors such as:
- Accreditation to ISO 17025 Standards. Such accreditation, by an organization such as A2LA (American Association for Laboratory Accreditation), insures that the vendor has proven their competency on the devices within the scope of their accreditation. For many quality systems, this is essential.
- For many devices, such as scales in the State of Michigan, the State requires that the vendor company and their technicians be registered with the State and that the technicians have passed competency tests.
- Your vendor should also have a solid relationship with the device manufacturer so that parts or replacements can be obtained easily, so that they are familiar with and have been trained on the equipment and in order to keep the warranty valid.
- Your vendor should also be able to provide you documents that outline their processes so that you are comfortable that the testing and calibration is being done as promised.
- You should also have timely delivery of and easy access to Certificates of Calibration. If you have special requirements for your certificates, your vendor should be able to meet those requirements.
- You should not have to worry about the scheduling of calibration services. Your vendor should have a system that automatically advises you when the services are due by phone, text or email. Timing compliance should be the vendor’s responsibility. Your concern should be with your core competency, not with quality system compliance issues.
In summary, buy from a reputable supplier, obtain proof of initial calibration, read the manufacturer’s recommendations, clearly describe the intended usage to the vendor and hire a vendor on whom you can rely to meet the requirements of your quality system and the expectations of your customer.
GRAND RAPIDS METROLOGY is such a supplier. With offices and calibration facilities in Grand Rapids, Battle Creek, Bay City, Benton Harbor and Metro Detroit, we cover the entire State. Our current scope of accreditation can be viewed HERE.