A meter with a small error value indicates that the meter has a high accuracy rating. In the field of industrial measurement, the accuracy level often represents the degree of quality of an instrument, it can be said that the accuracy level is one of the key indicators to measure the quality of the instrument.
There are three types of errors, namely: quoted error, relative error and absolute error.
One, quoted error
Quoted error = (absolute error of the maximum value / instrument range) × 100%, for example: 2% F.S.
Second, relative error
Relative error = (absolute error of the maximum value / instrument measurement value) × 100%, for example: ≤ 2%.
Three, absolute error
Absolute error refers to the error deviation from the true value of the size of the degree, for example: ≤ ± 0.01m3 / s.
Accuracy level, in fact, is the maximum quoted error value to remove the plus and minus signs and percentage signs. China's provisions of the size of the permissible error is divided into several levels. One of the industrial instrumentation accuracy level: 0.005, 0.02, 0.05, 0.1, 0.2, 0.35, 0.4, 0.5, 1.0, 1.5, 2.5, 4.0, etc., which, the smaller the grade level, the higher the accuracy level represented. In general, the precision level of industrial instruments for the 0.5 ~ 4 level, the instrument factory its accuracy will usually be marked on the instrument scale or its nameplate.
So how to calculate the accuracy of the meter? In fact, just follow the formula: meter accuracy = (absolute error of the maximum value / instrument range) × 100%. The above formula to take the absolute value and then remove the "%" is the value of the accuracy level.
Instrumentation accuracy is determined by the basic error limit of the sensor and the amount of influence (such as temperature changes, humidity changes, power fluctuations, frequency changes, etc.) caused by the limit of the amount of change.