In the use of the orifice plate flowmeter stage, its process piping needs to be blown many times, it is necessary to frequently disassemble the orifice plate flowmeter. If the size of the orifice plate is the same, a little inattention to errors, switching the orifice plate flowmeter will appear normal phenomenon. Orifice plate flowmeter upstream and downstream surface mounted on the reverse, in the installation of the pipeline to determine the direction of media flow and orifice plate flowmeter direction, otherwise it will lead to the measurement value is low. Caused by carelessness, in the installation of the orifice plate, to make the orifice plate flowmeter labeled "+" face in the upstream side of the flow direction. The main role of the pressure conduit is used to transfer the differential pressure signal generated by the orifice plate flowmeter, the length of the pressure conduit should be laid in the 3 to 20 meters between the distance, the pressure conduit, if too short, the flowmeter's flow measurement fluctuations will become large; if it is too long, then it will produce the measurement of the hysteresis phenomenon.

In the process of industrial production, most of the gas measurement is the use of standard throttling orifice flowmeter and differential pressure transmitter to support the use, although the accuracy of the differential pressure transmitter can reach a maximum of 0.075, but because of various reasons, the measurement error is also very large, will be used in the industrial measurement of the use of the transmitter, the problem will be even more obvious. So in finding the reasons for the measurement error and the way to overcome, are of great significance, orifice plate flowmeter is mainly by the guide tube, orifice plate, differential pressure transmitter is composed of, orifice plate flowmeter throttling device element will be the flow of the medium into a differential pressure, the differential pressure in the pressure-guiding pipeline through the transfer of sent to the positive and negative pressure chamber of the membrane box of the differential pressure transmitter, the positive and negative pressure chamber of the isolation of the diaphragm is through the silicone oil filler fluid to the measurement of the diaphragm. The isolation diaphragm of the positive and negative pressure chamber is filled with silicone oil to transfer the differential pressure to the measuring diaphragm, which can make the measuring diaphragm shift left and right.

Orifice plate flowmeters upstream and downstream surface will be damaged or orifice plate flange gasket protruding from the pipeline, in the transportation of the orifice plate flowmeter or in the process of installing the flowmeter in the construction workers, will cause upstream and downstream surface damage or flange gasket protruding from the pipeline, which will result in the flowmeter has a measurement error. Construction personnel in the installation of the orifice plate flowmeter should be carefully checked before the orifice plate, if found upstream and downstream surface damage to the orifice plate should be replaced in a timely manner. Standard orifice flowmeter design is derived from a large number of experiments, it does not require actual calibration can be used directly, the orifice flowmeter in the installation process may not be standardized or even the case of error, which will lead to flowmeter measurement errors.

Orifice plate flowmeters before and after the straight section does not meet the requirements of the straight section before and after the straight section is to ensure the stability of the fluid flow in the pipeline, but because the process pipeline will often be bifurcated, bends and other resistance to the emergence of pieces that will make the fluid due to the stability of the phenomenon into a perturbation, resulting in the measurement of the error. Can be used before and after the requirements of the straight section of the reasonable design of the installation position of the throttle device can be.