Uncertainties
Knowledge you need to have:
Knowledge of scale reading, random, and systematic uncertainties in a measured quantity.
All measurements of physical quantities are liable to uncertainty, which should be expressed in absolute or percentage form.
Scale reading uncertainty is an indication of how precisely an instrument scale can be read.
Random uncertainties arise when measurements are repeated and slight variations occur. Random uncertainties may be reduced by increasing the number of repeated measurements.
Systematic uncertainties occur when readings taken are either all too small or all too large. This can arise due to measurement techniques or experimental design.
The mean of a set of repeated measurements is the best estimate of the ‘true’ value of the quantity being measured. When systematic uncertainties are present, the mean value will be offset. When mean values are used, the approximate random uncertainty should be calculated.
Skills you need to develop:
Appropriate use of uncertainties in data analysis.
Use of an appropriate relationship to determine the approximate random uncertainty in a value using repeated measurements.
