Certified or Calibrated: What do you really want?


The terms Calibration and Certification have been used interchangeably for decades.

If you do a Google search:

 calibration versus certification_alliance calibration

The 442,000 results will provide more variations on the difference than really providing an answer.

A clear and concise 1- page explanation was provided by Quality Magazine in 2003 and is worth reading.

Click here to read the article in Quality Magazine.


It has been my experience that many people really want CALIBRATION when they ask for Certification.

Most often people are really wanting a Certificate of Calibration.

Unfortunately, the Chinese Menu of options offered by many companies offering Calibration and Certification makes it even more confusing.

 check markSticker only.

chinese_menu.jpeg check markSticker with Certificate.

check markSticker with Certificate and Data.

.check markSticker with Certificate and Data and Measurement Uncertainty.


 Calibration is the comparison of your measuring device against a known standard that is traceable through NIST( National Institute of Standards and Technology in the US) or another NMI(National Metrology Institute) to the SI unit.

If your device needed adjustment -  A STICKER ONLY will not inform you that adjustments were necessary.

A Sticker and Certificate without Data will not tell you how what was adjusted.

A Sticker with Certificate and Data without Measurement Uncertainty will not allow you to determine if the resolution between your device and the standard used in calibration is adequate to meet your risk requirements.

If you are looking for a detailed explanation of your risk as a consumer of calibration services, then we strongly recommend you read Measurement Decision Risk presented by NASA.

 ISO 17025 provides a framework for the consumer to have confidence in the calibration services they purchase.

Download  the  whitepaper How Using an Accredited Laboratory Benefits Government & Regulators

You may also want to read:

NIST Numbers: Your Auditor Is Wrong.

Out of Tolerance or Meets Specifications?


Phil Wiseman

Phil Wiseman

Phil Wiseman is Chief Marketing Officer at Alliance Calibration. He earned a B.S. in Chemical Physics from Centre College. Phil is an ASQ Certified Quality Auditor and ASQ Certified Manager of Quality/Organizational Excellence.

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