When a transverse magnetic field is used to a moving conducting fluid, the flowing conducting fluid cuts the magnetic field and induces a voltage. The fluid velocity, or flow rate, is proportional to the induced voltage.
Construction
The following are the key components of this magnetic flow meter:
The flow rate of a conducting fluid is to be monitored through a non-magnetic and non-conducting pipe. Two electrodes are linked to the pipe, conveying the conducting fluid on opposite sides. The flowing conducting fluid comes into touch with these electrodes. The pipe is enclosed by an electromagnet, which generates a magnetic field. Operation
This magnetic flow gauge is centered on Faraday’s induced voltage law, which is:
E = BLV
Where,
- E stands for induced voltage (volts)
- B is the flux density (Gauss)
- L = Conductor’s length, which is equal to the pipe’s diameter (cm)
- V = Average conductor (fluid) velocity in cm/sec.
When a conducting liquid flows through a conduit that is subjected to a magnetic field, the magnetic field is interrupted, resulting in a voltage. Because the magnetic field remains constant, the voltage measured between the electrodes is proportional to the average fluid velocity and diameter (length). It thus serves as a measure of volumetric flow rate.
Applications
- Flow rates of conducting fluids are measured with this device.
- Slurry, corrosive, and abrasive fluid flow rates are measured with this instrument.
- The magnetic flow meter is used to monitor bidirectional flows by automatically reversing connections.
Advantages
- Because these meters do not hinder flow, there is no pressure drop.
- It makes no difference whether the flow is laminar or turbulent for measurements.
- It provides precise findings.
- It has a high level of reliability, which means it provides consistent results over a lengthy period.
- It can work with oily materials as well as fluids with suspended particulates.
- The test is not affected by viscosity, density, temperature, or pressure.
Limitations
- Particular conduction conditions must be met by the fluid whose flow rate is to be monitored.
- To acquire accurate results, the fluid in the pipe should be filled.
- Errors are caused by air and gas bubbles in the fluid. The electrodes may become coated with scales when exposed to certain substances, affecting the output signal. Cleaning the electrodes, on the other hand, can take care of this.
- The output voltage is frequently low, necessitating amplification.
Conclusion
On the market, there are various types of magnetic flow meter, often known as mag meters. Each of these devices has a distinct purpose, yet they all follow the principles of Faraday’s law. Because different mag meters are used for other things, picking the right one and knowing how to use it effectively are critical for a successful fluid measurement project. When choosing this measurement equipment, consider variables such as dependability, precision, affordability, and user-friendliness.