There are many factors that affect the accuracy of the final detection results of measuring instruments, and any one of them will have a great influence on the measurement results, even subversive. To sum up, there are mainly several kinds, such as ratio difference and angular difference, impedance matching, range matching, transmission line loss, interference and so on.

Firstly, the influence of the ratio difference and angle difference of the sensor on the accuracy of the measuring instrument.

Ratio difference refers to ratio error. At present, the accuracy index of various sensors reflects the ratio difference, and the angular difference is the phase difference between the primary input and secondary output signals of AC signals. The angle difference directly affects the power measurement accuracy of the instrument. Under the same angle difference, the lower the power factor, the greater the power measurement error.

Second, the influence of impedance matching between sensor and analyzer on the accuracy of measuring instruments

For measuring instruments, impedance matching mainly refers to the matching between the output impedance of the sensor and the input impedance of the analyzer. For the voltage output sensor, when the input impedance of the analyzer is much greater than the output impedance of the sensor, it is generally considered as impedance matching.

For current output sensors, when the input impedance of the analyzer is much smaller than the output impedance of the sensor, it is generally considered as impedance matching. However, at present, users seldom consider impedance matching when choosing test equipment, which will have a certain impact on the measurement accuracy.

Instrument measurement accuracy:

Accuracy is the most important index to measure the performance of electronic measuring instruments, which usually consists of reading accuracy and range accuracy.

In measurement, the accuracy of any measurement can only be relative, and it is impossible to achieve absolute accuracy. There will always be errors caused by various reasons. In order to make the measurement results accurate and reliable, minimize the error and improve the measurement accuracy. We must fully understand the possible errors in measurement so as to take necessary measures to overcome them.

There are usually basic errors, compensation errors, absolute errors, relative errors, systematic errors, random errors, negligence errors and sampling errors in measurement.

Measurement accuracy is a measure to evaluate the measurement error from another angle, corresponding to the size of the error, that is, the error is large and the accuracy is low; Small error and high precision. Measurement accuracy can be subdivided into accuracy, precision and precision.