The output of the flowmeter is mainly linear and nonlinear square root. In general, the nonlinearity error of the flowmeter is not listed separately, but is included in the error of the flowmeter. For a generally wide flow range, the output signal is pulsed, used as a total flow meter, linearity is an important technical indicator, if a single meter factor is used in its flow range, when the linearity difference is Will reduce the accuracy of the flow meter. For example, a turbine flowmeter uses a meter factor in a 10:1 flow range. When the linearity is poor, its accuracy will be low. With the development of computer technology, the flow range can be segmented and fitted by least squares method. The flow-meter factor curve corrects the flowmeter to improve the accuracy of the flowmeter and extend the flow range.