6.01 Factors which determine the uncertainty in a measurement and limit precision
As previously stated precision refers to the degree of exactness in expressing a numerical value. The factors that affect the precision of the measurement value are;
- Resolution of the measuring instrument (precision can be further limited by the technique used to take the measurement!).
- Lack of clearly defined reference points to take the measurement from. (e.g. The measurement of the water level in a pond
when the surface is disturbed say by the wind blowing across it.)
- Variation in repeated measurements. (Repeating measurements often results in slight differences in the values obtained.
The width of the uncertainty interval in the measurement value must accommodate this variation.)
