Method for calibrating Coriolis mass flowmeter

Abstract

The invention provides a method for calibrating a Coriolis mass flowmeter. The method comprises the following steps of: firstly, performing estimated calibration on the meter, measuring an estimated zero point of the meter at zero flow of a full pipe, and setting the estimated zero point into the meter; selecting a larger flow point, measuring an estimated meter coefficient and setting the estimated meter coefficient into the meter; secondly, performing correction calibration on the meter, executing three flow accumulation experiments under each flow point, calculating an error of the accumulated mass flow under each flow point, obtaining a corrected coefficient of the estimated meter coefficient and a corrected coefficient of the estimated zero point by a linear fitting method according to the error so as to obtain a corrected meter coefficient and a corrected zero point, and setting the corrected meter coefficient and the corrected zero point into the meter; and finally, performing validation calibration on the meter, namely taking five flow points within a full measurement range of the meter, executing three flow accumulation experiments under each flow point, and calculating the error of the meter and the repetitiveness so as to determine a precision level of the meter. By the method, the precision level of the meter can be increased effectively.

Description

technical field [0001] The invention relates to the calibration field of flow meters, in particular to a calibration method of a Coriolis mass flowmeter which adopts estimation calibration, correction calibration and verification calibration in order to provide accurate instrument coefficient and zero point. Background technique [0002] Meter calibration is a verification link that the flow meter must first pass before leaving the factory or before actual application. Its purpose is to obtain the meter coefficient and zero point offset (hereinafter referred to as zero point) of the flow meter. have an exact correspondence. Therefore, the accuracy of the meter coefficient and zero point is directly related to the measurement accuracy of the meter. The Coriolis mass flowmeter is a flow meter that can directly measure the mass flow of fluids. The relevant verification specifications are given in the verification regulations (JJG1038-2008), which clearly defines the meter coef...

AI Technical Summary

Problems solved by technology

[0019] In summary, it can be seen that the error of the instrument coefficient and zero point of the flowmeter calibration will cause a constant error in the measurement result and an error that is inversely proportional to the actual flow

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