1. Firstly, both the insertion electromagnetic flowmeter and the insertion turbine flowmeter are based on the point velocity measurement principle, while the ultrasonic flowmeter is based on the line velocity measurement principle. After velocity distribution correction, it is basically equivalent to the surface velocity measurement, and its accuracy is higher than that of the above-mentioned flowmeters.
2. Other insertion instruments (referring to insertion turbines, electromagnetic, differential pressure, vortex shedding, etc.) all require the correction and compensation of the velocity distribution coefficient a, blockage coefficient, and interference coefficient. Inquire whether the user has carried out the correction and compensation when using other insertion instruments. Otherwise, certain errors will occur. However, the above factors basically do not affect the insertion ultrasonic flowmeter.
3. Other insertion instruments calculate the surface velocity of the entire pipeline based on the point flow velocity. Therefore, the requirements for the velocity distribution of the fluid in the pipeline are very strict. If the non-axisymmetric flow of the fluid in the pipeline is caused by insufficient straight pipe sections, it will cause certain errors in the measurement, or large errors due to flow distortion.
4. Understand the actual pipeline route on site, whether there are branch pipes, and whether there are sufficient straight pipe sections at the installation position.
5. Understand the service life of the pipeline, the actual outer diameter of the pipe, the actual wall thickness, the material, and whether there are inner linings and scaling phenomena inside the pipeline.
Post time: Apr-30-2025