5.01 Sources of error in measurement
As stated previously accuracy describes how close the measurement value is to the true value. this depends on the error in the measurement i.e. the difference between the true value and the furthest limit of the uncertainty interval. There are serveral factors which introduce error into measurements and limit accuracy.
The objectives of this section are to understand how accuracy is affected by :
- The measurement technique used
- The calibration of the measuring instrument used
- The precision of the measurement (which depends on the uncertainty in the measured value)
Measurement techniques will be discussed in detail later, good techniques can minimise errors and poor technique can introduce errors into the measurement. As an example consider parallax error. This is caused when the experimenter does not position their eye at the correct location to take a measurement and as a result they do not read the correct value from the instrument scale. (i.e. they read a value that is further away from the true value)