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Structural Analysis of Electromagnetic Flowmeter

Feb 16, 2017

Huaxheng  instrument intelligent electromagnetic flowmeter is based on the norms  of the manufacturing system and the development of its advanced design  concept to ensure that the products of high precision and high  reliability, compared with the old electromagnetic flowmeter, which has  high measurement accuracy, reliability Strong, good stability, full-featured, long life and other advantages. The structure of the electromagnetic flowmeter is mainly composed of  magnetic circuit system, measuring pipe, electrode, shell, lining and  converter.

1, measuring catheter: its role is to allow the conductivity of liquid through. In  order to make the magnetic flux through the measurement of the catheter  when the flux is shunt or short circuit, the measurement of the  catheter must be non-magnetic, low conductivity, low thermal  conductivity and a certain mechanical strength of the material made of  non-magnetic stainless steel, glass steel, high strength Plastic, aluminum and so on.

2, the magnetic circuit system: its role is to produce a uniform DC or AC magnetic field. DC  magnetic circuit with permanent magnets to achieve, the advantage of  the structure is relatively simple, by the AC magnetic field  interference is small, but it is easy to measure the conductivity of the  electrolyte through the catheter, the positive electrode is surrounded  by negative ions, the negative electrode is positive ions Surrounded  by, that is, the polarization of the electrode, and lead to two  electrodes of the locust resistance increased, thus seriously affecting  the normal work of the instrument. When the pipe diameter is larger, the permanent magnet is also a  large, cumbersome and uneconomical, so the electromagnetic flowmeter  generally use alternating magnetic field, and 50Hz power frequency  excitation generated.

3, shell: made of ferromagnetic material, is the distribution system  excitation coil cover, and isolation of external magnetic field  interference.

4, the electrode: its role is derived and measured proportional to the induced potential signal. The  electrodes are generally made of non-magnetic stainless steel and are  required to be flush with the lining so that the fluid passes  unobstructed. It should be installed in the vertical direction of the pipeline to  prevent sediment accumulation in the above and affect the measurement  accuracy.

5,  the converter: the liquid flow generated by the induced potential  signal is very weak, greatly affected by a variety of interference  factors, the role of the converter is the induction potential signal  amplification and conversion into a unified standard signal and inhibit  the main interference signal. Its task is to detect the induced potential of the electrode signal Ex is converted into a unified standard DC signal.

6,  lining: in the measurement of the catheter inside and flange sealing  surface, there is a complete layer of electrical insulation lining. It  is directly in contact with the measured liquid, its role is to  increase the measurement of the corrosion resistance of the catheter to  prevent the induced potential of the metal pipe wall short circuit. Lining materials are mostly corrosion-resistant, high temperature, wear-resistant PTFE plastic, ceramics and so on.