Calibration and Measurement Uncertainty

From: Endress+Hauser

Reading values from dials and taking measurement with devices is fairly standard procedure in any process. What we frequently neglect to consider is the fact that what we read does not necessarily match reality

 For various reasons, any measure is affected by errors. An experimental measurement can only be correctly interpreted if it is associated with an estimate of the probable error called 'measurement uncertainty'.

Metrology, the science that pertains to the theoretical and practical aspects of measurement tasks, is what we use to master the consequences of this uncertainty. In terms of quality management, industrial metrology involves managing the preparation and execution of measurement tasks in order to guarantee the measurement results, their traceability and their uncertainty.

Metrology is underutilized in industry because it is generally approached from the perspective of statistics or from the perspective of quality, but rarely from the perspective of its usefulness for the process.

But the real question concerning measurement uncertainty should be:

• What impact does it have?
• And how can the measurement be improved overall?

Take the case of a technician who, when performing an annual calibration, regularly finds values that are 'borderline' or even out of tolerance. Quite logically, he will make the decision to calibrate the device every six months instead.

While this decision is sure to cost the company more, its efficacy will in no way be certain. This is because the device must always be considered within the context of the measurement or calibration procedure.

For calibration services, many manufacturers must rely on a trusted outside specialist. Continuously developing standards in compliance with international norms such as ISO 17025, best practices in statistics and metrology, the service teams at Endress+Hauser are able to provide not just calibration, but also all of the materials and methods necessary to ensure the quality of the calibration service. On site or at one of the Group's many laboratories.

The extended article on industrial metrology and calibration can be read in our latest Maintenance Today #6 "Minimizing maintenance effort with maintenance, calibration and lifecycle solutions"

Forberg Scientific, Inc is now Endress+Hauser Authorized Service Provider (ASP) for Michigan and Northern Ohio.

Service can be scheduled by calling Forberg at 248-288-5990 Email: processsales@forberg.com or Endress+Hauser at 800-642-8737. With offices in Troy, Michigan, Cleveland, Ohio, and Grand Rapids, Michigan, Forberg Scientific has the resources and experience to meet your every need.

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