The measurement accuracy of E metering pump (%): under rated condition, the measured linearity (EL) stability precision and reproducibility precision (Es) (Era) a general term, usually expressed as a percentage of conventional products. Only the assessment precision stability and reproducibility of the pump. According to the national standard (GB/ T7782-2008 metering pump the required flow measurement accuracy) under rated condition and the maximum relative length of stroke of the metering pump should not be less than 1%..

API 675-1994 (R2000) "volumetric pump metering pump" standard stipulates that the repeatability of the flow should be within the specified regulation ratio of the rated flow of less than 3%

A) linearity (EL): at rated conditions, a single flow at any relative stroke length of the metering pump location value and the corresponding calibration flow difference of relative maximum flow ratio of EL=100% * /Qmax. (Qi-Qc).

B) stability accuracy (ES): the relative limit error between flow measurement and maximum flow measured at the same relative travel position under rated conditions

(c) reproducibility accuracy (Era): the relative limit error of a set of flow measurement values measured at discontinuous intervals for maximum flow metering pumps under rated conditions