The construction key consists of magnetic circuit system software, measuring conduit, electrode, housing, lining and converter.

Magnetic circuit system software: its function is to create symmetrical DC or AC electromagnetic field. The DC gas mass flow meter is maintained by * * * magnet, which has the advantages of simple structure and less influence of AC electromagnetic field. However, it is easy to make the liquid electrolyte solution in the measuring tube electrode, so that the positive electrode is surrounded by air anion and the negative electrode is surrounded by positive ionon, i.e. the electrode status, and causes The resistance in the middle of the two electrodes is enlarged, which seriously endangers the normal operation of the instrument panel. When the pipe diameter is large, * * * magnet is relatively large, heavy and uneconomical development, so electromagnetic flowmeter generally uses alternating electromagnetic field, which is encouraged by 50Hz DC switching power supply.

Measuring catheter: its function is to make the measured conductivity liquid according to. In order to make the magnetic induction line be separated or short circuited according to the magnetic flux when measuring the conduit, the measuring conduit must be made of non-magnetic, low conductivity, low thermal conductivity and raw materials with certain impact toughness. Non-magnetic stainless steel plate, glass fiber reinforced plastic anti-corrosion, high toughness plastic, aluminum, etc. can be used.

Shell: made of magnet raw materials, it is the shell of distribution mechanism excitation coil, and it protects the electromagnetic field of the principle of external electromagnetic flowmeter. Electrode: its function is to introduce the data signal of magnetic induction potential proportional to the measured value. The electrode is generally made of non magnetic stainless steel plate, and it is required to be flush with the lining, so that it will not be blocked according to the hydrodynamics. Its installation position should be in the vertical direction of the pipeline, so as to avoid the deposit on it which may endanger the measurement precision.

Lining: there is a layer of detailed insulation lining on the inner side of the measuring conduit and the flange protruding surface. The utility model directly contacts with the measured liquid, improves the corrosion resistance of the measuring conduit, and avoids the short circuit fault of the magnetic induction potential measured by the metal material wall thickness of the conduit. Lining raw materials are mostly anti-corrosion, heat-resistant, wear-resistant polytetrafluoroethylene plastic, porcelain, etc.

Converter: the data signal of Magnetic Induction EMF caused by metal rotameter is very weak, which is very harmful by various influencing factors. The converter's function is to enlarge the data signal of Magnetic Induction EMF and transform it into a unified standard data signal and suppress the key electromagnetic interference. Its daily task is to transform the magnetic induction potential data signal ex detected by the electrode into a unified standard DC data signal through increasing.