Calibration and Standards
A measurement device must have a trusted calibration and work with a known measuring error under the conditions prevailing when the measurement is made.
These can be difficult to determine at times and require some special skills. Then, too, they can be really straight forward and a trivial task.
Learning how to evaluate a measuring device’s calibration performance under real world conditions is key to successful use, because measurement technology is a science and subject to the same quotation by Lord Kelvin. Another way of looking at the situation, is: garbage in-garbage out.
If you lack certain quantitative detail, in numbers, about a measurement device then its measurements are likely to be “meagre” and unsatisfactory kind, also.
Calibration is related to the science behind a given measurement device and is often supported by a traceable chain of records to more accurate measurement devices, sometimes called standards.
Then, too, there are standardized methods for using and calibrating, even in fabricating some types of measurement devices. These are often contained in documents called standards or standard practices.
We’ve progressed quite a long way from the length of an English king’s thumb, arm or foot as a measurement standard. The agreed international standard for length, for instance, is defined as the wavelength of light emitted by a specific type of atom.