Why Calibrate ?

Or "Calibration? How does that help me?"

British scientist Lord Kelvin (William Thomson 1824-1907) is quoted from his lecture to the Institution of Civil Engineers, 3 May 1883...
"I often say that when you can measure what you are speaking about and express it in numbers you know something about it; but when you cannot express it in numbers your knowledge is a meager and unsatisfactory kind; it may be the beginning of knowledge but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be."

This famous remark emphasizes the importance that measurement has in science, industry and commerce. We all use and depend upon it every day in even the most mundane aspects of life -- from setting your wristwatch against the radio or telephone time signal, to filling the car fuel-tank or checking the weather forecast. For success, all depend upon proper calibration  and traceability to national standards.

As components age and equipment undergoes changes in temperature or sustains mechanical stress, critical performance gradually degrades. This is called drift. When this happens your test results become unreliable and both design and production quality suffer. Whilst drift cannot be eliminated, it can be detected and contained through the process of calibration.

Calibration is simply the comparison of instrument performance to a standard of known accuracy. It may simply involve this determination of deviation from nominal or include correction (adjustment) to minimize the errors. Properly calibrated equipment provides confidence that your products/services meet their specifications. Calibration:

• increases production yields,
• optimizes resources,
• assures consistency and
• ensures measurements (and perhaps products) are compatible with those made elsewhere.

By making sure that your measurements are based on international standards, you promote customer acceptance of your products around the world. But if you're still looking to justify that the cost of calibration does add value, check-out some of the calibration horror stories that have been reported.

• Calibration Horror Stories

Of course, even with proper calibration it's still possible to make bad measurements if the equipment isn't correctly used.

• Procedure Adequacy

But also consider the reliability of the calibration supplier.

• Proper Calibration

And Finally...

Lord Kelvin also expressed some opinions that, with the benefit of hindsight, he would have wished not to have voiced !

•   " There is nothing new to be discovered in physics now. All that remains is more and more precise measurement. "
•   " I can state flatly that heavier than air flying machines are impossible. "
•   " Radio has no future" and  "Wireless is all very well but I'd rather send a message by a boy on a pony ! "