For information on how Instrument Repair & Calibration can help your company, please visit our Calibration Services page.
What is "calibration"?
verb | cal·i·brate \ ˈka-lə-ˌbrāt \
To standardize (something, such as a measuring instrument) by determining the deviation from a standard so as to ascertain the proper correction factors.
CALIBRATE
Merriam-Webster
Why we calibrate.
It starts with measurement.
Measurement is a process that checks whether something is correct within a set of specified limits; the process by which we obtain a value of a quantity which is expressed as the product of a numerical value and a measurement unit (numerical value • unit).
Example:
Length of a rod 3.25 m
(3.25 • 1 m)
Mass of a body 10.2 kg
(10.2 • 1 kg)
Temperature of a body 55 °C
(55 • 1 °C)
A measurement unit is a defined quantity of size “one” used as unit.
Example:
Unit for length 1 meter
(1 m)
Unit for mass 1 kilogram
(1 kg)
Unit for temperature 1 kelvin
(1 K)
It is standard within the industry to use measurement units known as (SI) as defined by the International Bureau of Weights and Measures (BIPM).
Next comes traceability.
The concept of traceability in metrology is that a measurement result is based on comparison with an SI rather than a statement of quantity.
3.25 m as a measurement of length means
the item is actually 3.25 times the stated unit of measurement (1 m)
as defined in the International System of Units (SI).
Traceability is obtained by calibration — establishing the relation between the indication of the measuring equipment and the value of a measurement standard — which in turn has an established relation to the definition of the SI unit (also obtained by calibration).
Traceability represents the uncertainty within a measurement.
-
All measurement means a comparison, directly or indirectly, with a measurement standard that has an uncertainty
-
No measurement can be done perfectly so the measurement itself will always add some uncertainty
+
The measured value and its uncertainty defines an interval that with a certain probability (usually 95%) covers the “true value” of what is measured.
Calibration is key.
Whether it’s a simple gage, scale or thermometer; or a more advanced measuring system such as a coordinate measuring machine (CMM); a laser or vision based measuring systems; or electrical instruments like power supplies, multimeters, oscilloscopes, signal generators or spectrum/signal analyzers; measurement equipment is important. And for every one of these, calibration is essential to ensure accuracy.
Calibration provides a documented traceability for the measuring equipment known as the calibration certificate. Additionally, frequent calibration brings fewer uncertainties and less risk.
When to calibrate:
1
Before use to ensure that it is in compliance with required measurement standards.
During use adjustments should be made as needed to ensure accuracy.
2
3
After use to assess the validity of previous results, and to prepare it for its next use.
info via Quality Magazine.
Please visit our Calibration Services page to find out how Instrument Repair & Calibration can help your company.