Who can be against apple pie, motherhood, or good measurements? This is why everyone stands up and salutes when we are told to maintain our measurement systems in good calibration. But what is good calibration? By what method will we achieve it? And how will we know when we have it?

One day I found the following statement about measurement consistency and calibration in a well-known company’s laboratory procedure document: “It is the testing department supervisor’s responsibility to make sure that the testing equipment is current and in good calibration before testing any samples.” Nothing else was included. This was the end of the sentence, the end of the paragraph, and the end of the topic. While statements like this serve to identify who is the scapegoat when things go wrong, they give no guidance on what good calibration is, how to achieve it, or how to know it when you see it.

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