What Is Calibration?
There is an important distinction between calibration and adjustment. Calibration is about developing an understanding of a measurement device and how it behaves. If it does not behave as it should, adjustments are made to ensure the device performs according to its specifications, to deliver accurate measurement results.
The International Bureau of Weights and Measures (BIPM) defines calibration as an ‘operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication.’
Calibration and adjustment are two separate things; you can calibrate a measurement device without adjusting it, and this is very often the case.
A weighing device is calibrated to understand how it is behaving. If the results do not meet specifications, the device is then adjusted to ensure the accuracy of the measurements. With a focus on weighing devices, this white paper discusses the concept of calibration – what it is and what it is not – and explains the difference between calibration and adjustment.