A flowmeter, as the name suggests, is a device that is used to measure the flow of a fluid moving in a bulk stream.The full bore electromagnetic flow meter
,also known as a magmeter, measures the volumetric flow rate of the fluid by recording the voltage generated by it while passing through a magnetic field. Electromagnetic flow meters have been in use for more than half a century.
How it works?
The typical design of a magmeter consists of a pipe that has wire coils which are mounted on the outside. This pipe is has an electrical insulating surface like a steel tube lined with rubber. When a voltage is applied on the wire coils, it generates a magnetic field in the pipe. Now, when the conductive fluid passes though this magnetic field in the pipe, it generates a voltage. Electrodes mounted on the sides of the pipe detect this voltage and the flow rate is calculated from this voltage levels.
One essential thing to keep in mind is that a in-line magnetic flowmeter sensor works only for conductive fluids like water, acid, waste water.,etc, so it often been used as waste water flow meter, acid resistant flow meters
, chemical flow meter, aggressive liquid flow meter.,etc. If used with non conductive fluids like hydrocarbon-based liquids, such as diesel, oil, the voltage will not pass through them and hence there will be no reading captured by the electrodes.
An electromagnetic meter has a few advantages over other types of flowmeter, like the following-
They can easily be used to measure flow of dirty liquids like slurries, pulp and waste water. They can also measure the flow rate of other hard to measure fluids. And even though Doppler flowmeters can also handle all such fluids, they are not efficient enough for the purpose. Another unique advantage is the availability of several types of liners for the magnetic flow sensors. This makes the process more hygienic and allows the flow rate of almost any kind of fluid to be measured using the suitable liner type.
The popularity of battery operated magmeters is on the rise. Sometimes these battery operated devices are installed in remote locations for measuring flow rates for fluids like waste water, irrigation water. They are also used to measure the flow rate of water from agriculture, irrigation, distribution channels and networks, etc. In all these cases not only are the devices battery operated, but they have wireless connectivity. This feature makes it possible to gather 'Automated Meter Readings (AMR)' from obscure locations, now we can also provide GPRS magnetic flow meter.
Future Research on mag meter
An area where there is ongoing research for the magnetic flowmeters, is on reducing the conductivity levels of the fluid required to capture the readings. By taking inspiration from how the transit-time meters have been optimized to handle more impure liquids, magnetic suppliers have been successful in reducing the minimum conductivity required to measure the flow rate. Though this research may not be as useful to measure flow of fully conductive fluids; it definitely increases versatility of the devices.
Presently, the magnetic flowmeter market is rapidly growing, second only to the differential pressure (DP) flowmeter in terms of revenue. The growth in population is the major reason for increase in the use of the magmeter. This is because the full bore electromagnetic flow meter is used extensively to measure flow of clean and waste water. Additionally, these devices are also being used in place of turbines and other positive displacement meters in some cases. Both of these factors together will result in a further growth in the mag flowmeter market in the coming years.