interprets the main measurements to ensure the measurement accuracy of the orifice flow meter –

When the orifice flow meter is measured on site, the measurement results often have large errors due to some objective factors. The following introduces the main measures to ensure the measurement accuracy of the orifice flow meter:

1. The orifice flow meter is calibrated one by one. As we all know, as long as the standard orifice plate is designed and manufactured according to relevant standards, it can be used directly without real flow calibration. Because the flow coefficient can be directly calculated by the software, but the calculation by computer is finally ideal, and there is always some difference with the on-site environment. Therefore, in order to ensure the accuracy of the measurement, it is recommended to perform an actual flow calibration for each flow meter and the calibrated flow. The coefficients are compared with the results of the calculation, and the difference is calculated and corrected.

2. CoReynolds number reduction. There is a definite relationship between the flow coefficient of the orifice flowmeter and the Reynolds number. When the mass flow changes, the Reynolds number changes proportionally, thus causing a change in the flow coefficient.

3. The influence of temperature on the orifice flowmeter and its correction. The change in temperature of the fluid causes the change in density, which causes the relationship between differential pressure and flow rate to change. Second, the temperature change causes the inner diameter of the pipe and the opening of the orifice plate The correction of the temperature change is to take the temperature instrument to measure the temperature on site, and then enter it into the secondary instrument to correct the error caused by temperature change.

4. Correction of swelling capacity. When the orifice flow meter measures the flow of steam andgas, fluid expansion must be corrected. For the specific correction coefficient, please refer to the throttling device design manual.

5. Calculation of steam mass flow. When the orifice plate flow meter measures the steam, the flow rate value is first obtained from the differential pressure signal, and then the density is obtained by consulting the temperature and pressure of the steam to calculate the flow quality of steam.

In fact, the orifice flow meter is widely used to find the flow rate, and it is also a representative of the differential pressure flow meter. You can use appropriate inferences to promote other differential pressure flowmeters.

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