LIMITTING ERROR
The accuracy of measuring instrument is guaranteed within a certain percentage of full scale reading.
As an example;
Supposed the accuracy of a 0-100V voltmeter is specified as 2% of full scale range. This implies that the error is guaranteed to be within 2V for any reading. If the voltmeter reads 50V, then the error also within 2V. As a result, the accuracy for this reading will be:
(2/50) x 100 = 4%
Limiting error of an instrument = % accuracy x full scale
Limiting error of a measurement (%)
= (magnitude of limiting error / measurement) x 100