Electromagnetic flow meters consist of sensors and transducers. Due to the principle and structure characteristics, the sensor has the following main advantages:
(1) The structure is simple, there are no moving parts and disturbing parts or throttling parts that hinder the flow of the measured medium, and no problems such as blockage and abrasion of the pipeline will occur. Therefore, the electromagnetic flowmeter is particularly suitable for measuring liquid and solid two-phase media, such as with suspended solids, solid particles, fibers, or conductive pastes with high viscosity. Can be used to measure the flow of sewage, mud, pulp, pulp, chemical fiber pulp and other media. Because the measuring tube is a straight tube, it does not leave media, and it is easy to clean and disinfect. Therefore, it is also particularly suitable for the food and pharmaceutical industries. It is used to measure the flow of special media such as corn syrup, fruit juice, liquor, medicine and blood.
Because there is no throttling device, when the measured medium flows in the sensor measuring tube, there is almost no pressure loss, and only 10 to 20 W of electric power is consumed. Compared with the differential pressure flow meter with throttling, the energy saving effect is very prominent. Take the pipe diameter d: 1m, flow q, = 6000m3/h as an example. If a venturi pipe is used with a differential pressure transmitter of 40kPa, the permanent pressure loss will result in extra power consumption of the pump. lOkW; When using an orifice flowmeter with a 40kPa differential pressure transmitter, the additional power consumption of the pump is approximately 32kW. For today's increasingly urgent energy-saving requirements, energy conservation has been valued by people, and energy conservation has become a major advantage in the development of electromagnetic flowmeters.
(2) Electromagnetic flowmeter is a kind of instrument for measuring volume flow. Its measurement is not affected by fluid density, temperature, pressure, viscosity, Reynolds number and the change of conductivity within a certain range. Electromagnetic flow meters require only water as the test medium for calibration and can be used to measure other conductive liquids without the need for additional corrections. This is an advantage that other flow meters do not have.
(3) The electromagnetic flowmeter has a wide range of measurement. For the same caliber sensor, the full-range flow rate is arbitrarily set in the range of 0.3 to 15 m/s, that is, the upper limit range (range ablity) is 50:1; each range can also be linearly measured from 2% to 100%. Turn down is 50, and the total measurement range can reach 2500:1. Electromagnetic flow meter can be measured
Covering turbulent flow and laminar flow in two speed distribution states, this is a differential pressure flow meter, turbine, vortex and other flow meters can not be compared with it.
(4) The measurement principle is linear, the measurement accuracy is high, up to ±O of the indicated value. 2% to ±0.5%. Therefore, it can be used as a measuring instrument for industrial production process inspection and trade settlement. Complete electrical signal output, fast measurement response, pulsating flow and rapid cumulative total. With a unified current, frequency signal and digital communication signal output for remote transmission, indication, recording and control.
(5) Good corrosion resistance. Since the sensor has a rubber, fluorine plastic or industrial ceramic material lining, and other parts of the contact with the measured medium only the electrode and grounding ring, use different electrodes and grounding ring material, can easily solve the corrosive fluid measurement.
(6) In principle, the mean velocity of the cross-section of the water is measured. The signal is distributed according to the weight distribution area, and the requirement for the flow velocity distribution is low. Therefore, straight sections before and after the sensor are required to be shorter than other flowmeters. The mounting of the sensor can be horizontal, vertical or at any angle (but the fluid preferably flows from bottom to top).
(7) The flow of fluid in both positive and negative directions can be measured.
(8) The use of reliable, easy maintenance, long life.