level of accuracy
The accuracy level and maximum allowable error of the flowmeter within the specified flow range should meet the requirements of Table 1. The flowmeter error indicates the relative indication error.
Accuracy level and maximum allowable error
Accuracy level 0.2 (0.25) (0.3) 0.5
Maximum allowable error ±0.2% (±0.25%) (±0.3%) ±0.5%
Accuracy level 1.0 1.5 2.5 /
Maximum allowable error ±1.0% ±1.5% ±2.5% /
Note: Priority is given to grades without parentheses
For the flowmeter error indication used for instantaneous flow indication, the quoted error can also be used. The maximum allowable error series should meet the requirements of Table 1. The accuracy grade is no longer given in the bidding document of the verification result, and the maximum allowable error expression is used, and FS should also be marked after the maximum allowable error, such as ±0.5%FS.
In a calibration of a flowmeter, the method of indicating the error of the flowmeter should be given according to one of the accuracy grade and the quoted error; for the flowmeter that uses the combination of relative indication error and quoted error to indicate the error, a calibration is in progress A method should also be used to express the error.
The repeatability of the flowmeter shall not exceed 1/3 of the absolute value of the maximum allowable error specified by the corresponding accuracy level.