The best way to define Uncertainty Components is by the SWIPE method.
There are, in general, two kinds of uncertainties in measurements of engineering variables: random uncertainty and systematic uncertainty.
Measurement uncertainty is usually divided into two components:
- Type A uncertainty expresses the random error in the data, typically caused by noise and similar environmental conditions. Its evaluation is based on statistical tools. In most cases, the best estimate of the result is given by the arithmetic mean which is given for a set of N measurements of quantity
- Type B uncertainty describes a systematic error that could be present in the result and we do not know it to a level that we could correct it. This uncertainty is usually evaluated using Gauss law for the propagation of uncertainties. We first construct a mathematical model of the measurement—an equation describing the measurement process including the systematic error sources.
The best way to define Uncertainty Components is by the SWIPE method.
- S: Standard= All Uncertainty components related to Standard like Uncertainty, Accuracy
- W: Work piece= All Uncertainty components related to workpiece like the least count
- I: Instrument= All Uncertainty components related to Equipment/Instruments like Uncertainty, Accuracy
- P: Person or Process= Mostly covered in Type A Uncertainty, You can also consider least count here
- E: Environment Factors= Some of the common components are Soaking difference, Difference in thermal coefficient of expansion of material between Devices under Calibration & Master Equipment used, Overall Temperature Measurement system uncertainty in the lab, etc.
