Meter

Meter, the numerical value of the instrument, including pressure gauges flow meters, as well as a variety of analytical instruments, etc..

In engineering type instrument performance index usually with accuracy (also known as precision), variation, sensitivity to describe.

Instrument calibration instrument is usually adjusted accuracy, variation and sensitivity of three. Variation refers to the instrument measured variables (can be understood as the input signal) several times from different directions to reach the same value, indicating the maximum difference between the value of the instrument, or is the instrument in the outside world under the same conditions, the measured parameters from changes (positive characteristics) and the measured parameters varies from large to small (reverse characteristics) inconsistent degree, the difference between the two is the instrument of variation. Ratio of the maximum absolute error to the range of the instrument scale:

The main cause of variation is the clearance of the instrument, the friction of the moving parts, the lag of the elastic element, etc.. With the continuous improvement to instrument manufacturing technology, especially the introduction of microelectronic technology, many electronic instruments, no moving parts, analog meter into digital instrument and so on, so the variation index in intelligent instrument is less important and prominent.