Electromagnetic flowmeter measurement principle is Faraday's law of electromagnetic induction, mainly used to measure the volume flow in closed pipelines of conductive liquids and slurries, including acids, alkalis, salts and other highly corrosive liquids.
Supmea below introduces three aspects that need to be paid attention to during the installation of electromagnetic flowmeter.
1. Pay attention to the selection of installation site
The electromagnetic flowmeter should be installed in a place where there is no negative pressure in the measuring tube; avoid installing it near strong electric equipment such as motors and transformers to avoid electrical interference; avoid installation in places with strong corrosive gases around the installation location; when measuring mixed-phase fluids, avoid places that cause phase separation; the ambient temperature should generally be within the range of -25℃ to 60℃, and avoid direct sunlight as much as possible; install it in a vibration-free or low-vibration place. If the vibration is too large, fixed supports should be added to the pipes before and after the sensor; the relative humidity of the environment should be within the range of 10% to 90%; avoid installation in places where it can be directly exposed to rain or immersed.
2. Pay attention to the requirements of the length of the front and rear straight pipe sections
The electromagnetic flowmeter has relatively low requirements for the front and rear straight pipe sections. Generally, for flow resistance parts such as 90° elbows, T-shaped tees, reducers, fully open valves, etc., there should be a 5D straight pipe section away from the center line of the electrode axis of the electromagnetic flowmeter (not the end face of the sensor); for valves with different openings (such as valves with adjustable openings), the straight pipe section length on the upstream side needs to be 10D.
3. Pay attention to the installation position and flow direction
Electromagnetic flowmeters can be installed horizontally, vertically, and obliquely on pipelines. The measuring pipeline of the sensor must be filled with fluid and must have a certain back pressure. To prevent negative pressure (damage to the lining), the electromagnetic flowmeter should not be installed at the inlet of the pump, but at the outlet of the pump. When installed horizontally, the electrode axis of the electromagnetic flowmeter must be horizontal to prevent short-term insulation of the electrode due to bubbles entrained by the fluid, and to prevent the electrode from being covered by sediments in the fluid. The sensor should not be installed at a high position to avoid gas accumulation. When installed vertically, the flow direction should be upward, so that when there is no flow or the flow is very small, the heavier solid particles entrained in the fluid will sink, while the light limb fat substances will rise and leave the sensor electrode area of the electromagnetic flowmeter, and when measuring mud and ore liquid solid two-phase media, solid phase precipitation and uneven friction of the sensor lining can be avoided. When installed obliquely, it must be installed in the rising pipeline; when installed in an open discharge pipeline, it must be installed at the lower part of the pipeline.
Hangzhou Economic Development Area，Hangzhou 310018，China
