Comparison of the results of pressure gauge online verification and traditional verification
For the same pressure gauge with a measuring range of (0～1.6) MPa and an accuracy grade of 1.6, after online verification, it will be disassembled and sent to the laboratory for offline verification using traditional verification methods. Verification and offline verification strictly follow the current verification procedures. [1, 2] In order to facilitate verification of verification results, the standard pressure gauge selected for online verification is (0～1.6) MPa, and the standard pressure gauge with an accuracy level of 0.25, offline verification The standard instrument selected at the time is (0～1.6) MPa, and the accuracy grade is a digital pressure gauge of grade 0.05.
According to the verification method of the verification results, the difference between the two verification data of the same verification point of the stainless steel pressure gauge does not exceed the uncertainty of the measured value of the offline verification (a higher level of measurement standard). The online verification result is verified, which proves the online verification method. reliable.
4 Precautions for online verification.
(1) The pressure gauge is used in complex on-site environmental conditions, and attention should be paid to checking whether the on-site environmental conditions meet the requirements of the verification regulations in the online verification.
(2) When the daily use medium of the tested meter is inconsistent with the medium used during verification, the daily use medium should be used after the standard device and the pressure generator are removed and before the D gate valve is connected (that is, the original pipeline is connected) Clean the four-way pipe to prevent pipeline contamination, and pay attention to isolation during online inspection of the oil-free gauge
