Measurement error of metal rotor flowmeter

Project Overview

The metal rotor flowmeter is a variable area flowmeter based on float position measurement. It is a commonly used flowmeter in industry and laboratories. More and more steel and chemical companies are evaluating the measurement uncertainty of the indication error of metal rotor flowmeters.

1. Measurement standard: sonic nozzle airflow standard device, working range DN mm diameter. The sonic nozzle gas flow standard device mainly consists of a ring water vacuum pump, a pressure stabilizing tank, a calibration table, a sonic nozzle, a timing counter, a host computer, etc.

2. Large changes in the density of the liquid medium will also cause measurement errors. Viscosity DN15 ≤ 5 MpA·s; DN25-DN 100 ≤ 250 MPa. If the density is larger, the changed medium density is converted into an error correction coefficient, and then the flow rate measured by the metal rotor flowmeter is multiplied by the coefficient and converted into the actual flow rate.

3. Due to long-term use, pipeline vibration and other factors, the moving parts such as the induction magnet, pointer, counterweight, and rotating magnet of the metal rotor flowmeter have become loose, resulting in large errors. Solution: You can verify it by first pushing the pointer with your hand. First, press the pointer at the RP position to check whether the output is 4mA and whether the flow rate display is 0%, and then verify according to the scale in sequence. If any differences are found, the position of the parts can be adjusted. Generally, professionals are required to make adjustments, otherwise the position will be lost and need to be returned to the manufacturer for correction.

In summary, the deflection caused by the elbow reduces the imbalance of the float force, which is of reference significance for improving the measurement accuracy of the flow meter.