Previous we have talk about Measurement uncertainty. Today we touch on source of the uncertainty coming from.

The uncertainty of the result of a measurement reflects the lack of knowledge of the value of the measurement.

Here we list out the possible sources of uncertainty:

1. Incomplete definitions of the measurand. 
2. Imperfect realisation of the definition of the measurand. 
3. Sampling - the sample measured may not represent the defined measurand. 
4. Inadequate knowledge of the effect of environmental conditions on the measurement procedure. 
5. Personal bias in reading analogue instrument. 
6. Instrument resolution or discrimination threshold.

Above is possible can lead to source of uncertainty happen. Reduce above can help to obtain proper measurement.