Who Do You Trust?
I’m not referring to an old time game show or parlor game as they used to be known. My question is, “Can you trust your vendor’s calibration certificate?”
There are a few indicators you can use.
- What kind of reputation does the company have in the industry? You know, how long have they been around and do other customers respect their products and service? There are a number of industry surveys and reports that can help with this if you don’t feel comfortable making your own assessment.
- Is the certificate traceable to NIST or other national standards body? This may seem obvious, but read the statement see if it makes sense to you. Are there unsupported assertions about things like TUR (Total Uncertainty Ratio) or Guide 25 approval?
- Are the standards used properly identified and are they appropriate for the task at hand? For example, if a specification is % of reading, but the standard’s specification is % of scale, there’s a significant mismatch. You may also need to check to see if the standard has been properly maintained with acceptable calibration intevals.
- Does the certificate include data that is clearly presented and meaningful? Are there sufficient data points to assess performance?
- If possible, check the calibration at intervals different from the cardinal points on the certificate. Even a bump check can provide revealing information.
Finally, is the calibration accredited under an international standard (ISO 17025) or do you need such an accredited calibration. Even if it’s offered as an option, the vendor must have a pretty good idea that the normal calibration is valid.
Tags: accuracy, calibration certificate, calibration uncertainty, good business tips, Martel Electronics, quality, standards, traceability