Take you to understand the structure of the electromagnetic flowmeter

The electromagnetic flowmeter is a new type of flow measuring instrument
that developed rapidly with the development of electronic technology in the 1950s and 1960s.

Electromagnetic flowmeter is an instrument
that applies the principle of electromagnetic induction to measure the flow of conductive current according to the electromotive force generated by the conductive fluid when it passes through the applied magnetic field.

The structure of the structural electromagnetic flowmeter is mainly composed
of a magnetic circuit system, a measuring tube, an electrode, a housing, a lining, and a converter.

Magnetic circuit system: Its role is to generate a uniform DC or AC magnetic field
.

DC magnetic circuit with magnet to achieve, its advantage is that the structure is relatively simple, by the AC magnetic field interference is small, but it is easy to make the electrolyte liquid polarization through the measurement tube, so that the positive electrode is surrounded by negative ions, the negative electrode is surrounded by positive ions, that is, the polarization phenomenon of the electrode, and leads to an increase in the internal resistance between the two electrodes, thus seriously affecting the normal operation of the
instrument.

When the diameter of the pipe is large, the magnet is correspondingly large, bulky and uneconomical, so the electromagnetic flowmeter generally uses an alternating magnetic field, and is generated by
the 50HZ power supply excitation.

Measuring catheter: Its role is to allow the conductive liquid under test to pass
.

In order to make the magnetic field line through the measurement of the catheter magnetic flux is shunted or short circuit, the measuring catheter must be made of non-magnetic conductivity, low conductivity, low thermal conductivity and mechanical strength of the material, can choose non-magnetic conductivity stainless steel, fiberglass, high-strength plastics, aluminum and so on
.

Electrode: Its role is to elicit an induced potential signal that is proportional to the measured potential
.

The electrodes are generally made of non-magnetic stainless steel and are required to be flush with the lining so that fluid passage is not hindered
.

Its installation position should be in the vertical direction of the pipe to prevent sediment from accumulating on top of it and affecting the measurement accuracy
.

Housing: made of ferromagnetic material, is the distribution system excitation coil cover, and isolates the interference
of the external magnetic field.

Lining: On the inside of the measuring tube and on the flange sealing surface, there is a complete layer of electrically insulated lining
.

It is in direct contact with the liquid being measured, and its role is to increase the corrosion resistance of the measuring catheter and prevent the induced potential from being short-circuited
by the wall of the metal measuring catheter.

The lining materials are mostly corrosion-resistant PTFE plastics, ceramics and so on
.

Converter: The induced potential signal generated by the flow of liquid is very weak, greatly affected by various interference factors, and the role of the converter is to amplify and convert the induced potential signal into a unified standard signal and suppress the main interference signal
.

Its task is to amplify the induced potential signal detected by the electrodes into a unified standard DC signal
.