The difference between electromagnetic flowmeter and ultrasonic flowmeter

To measure how the liquid flows through the pipes, we use two types of flowmeters. The electromagnetic flowmeters and the ultrasonic flowmeters are the two types of flowmeters we will discuss. Both of these tools tell us how much liquid flows in the pipes, but they work in different ways. Let’s take a closer look at how each of these flowmeters works and what differentiates and enables them to be usefuol. 

How They Measure Flow?

An electromagnetic flowmeter is a special electric tool that is used to measure flow at low velocities of conductive juices such as water. As the liquid moves through the pipe, it generates a phenomenon known as a magnetic field. It is a force the liquid creates by its motion. The inside of the flowmeter consists of two sensors known as electrodes which are inserted in the liquid and set perpendicular in relation to the flow direction of the liquid. And these are when we put electricity on — when we connect electricity to the electrodes, it creates a current. This flow of current helps us determine how quickly the liquid is moving. The air flow meter can tell us the flow rate (the amount of liquid that passes a certain point over a certain amount of time) by measuring this current.  

Ultrasonic Flowmeter

An ultrasonic flowmeter is used to measure the passenger of liquid with the help of ultrasonic waves. This flowmeter transmits sound waves through a liquid flowing within a pipe, and measures how long it takes for sound to travel between two sensors. As the fluid flows, it alters the propagation of the sound waves. In other words, if the liquid is flowing, sound waves will move faster in the direction of the flow, and slower in the opposite direction. When you check the time of travel, the flowmeter can compute the flow rate of the liquid accurately. 

Understanding How They Work? 

Electromagnetic Flowmeters

These oxygen flow meter work on a particular principle, known as Faraday's Law. This law states that when an electrical conducting liquid moves in the presence of a magnetic field, an electric field is set up. It is necessary to evaluate the speed of the liquid which relies on the aforementioned electric field. This electric field can subsequently be measured by the flowmeter, which can determine the flow rate from the intensity of the field. 

Ultrasonic Flowmeters

Ultrasonic flowmeters operate on the Time of Flight Principle. That means that they send a burst of sound waves through the liquid and measure the time it takes for the waves to get to the other sensor. If the fluid is flowing in the pipe, the waves will propagate faster along the fluid flow direction and slower against it. The flowmeter can calculate how fast the liquid is moving by measuring how long it takes for the waves to make a round trip. 

The Accuracy and Reliability Faced Off

Electromagnetic flowmeters, as the name implies, enable the measurement of low conductivity fluids based on Faraday’s law of electromagnetic induction. 

Another way to measure flow accurately is through the use of electromagnetic flowmeters, but these only work for clean liquids that conduct electricity. They can measure flow in both directions, giving us insight into how much of a liquid flows in and out of a system. They also perform well at a wide spectrum of flow rates. Electromagnetic flowmeters can also cause issues if there are bubbles or solids in the fluid, however. This noise can affect the readings of voltage and thus make the flow readings inaccurate.

In addition, ultrasonic flowmeters perform accurately even in very non-circular pipe - with well known exceptions of non-conductive liquid. They don't feel disturbed by bubbles or solids. Ultrasonic flowmeters can, however, have trouble measuring flow rates in small pipes and low flow conditions. It also means that their readings might not be the best in all circumstances.

Choosing the Right Flowmeter

When picking a suitable flowmeter, there will be a decision to be made between electromagnetic or ultrasonic, and which has a specific application of the liquid being measured, the flow rate, and if there are, in flow, distorted environments. Electromagnetic flowmeters are most suitable for clean, conductive liquids, and for applications where the flow volume is large. Ultrasonic flowmeters, on the other hand, should be used with non uniform pipes and legitimate non-conductive fluids.

And also, you need to remember about the diameter of the pipe you are measuring. In small pipes, ultrasonic flowmeters are not very accurate at low flow measuring. This is worth considering when you select the best flowmeter for you. 

Pros and Cons of Each Type of Flowmeter

Because of this, flowmeters can be classified into two types, each with its own advantages and disadvantages. Electromagnetic flowmeters are more precise, but need clean, conductive liquids, to begin with, before they can operate correctly. Ultrasonic flowmeters, on the contrary, are more immune from this kind of progress and can operate with non-conductive fluids. However, they struggle to measure low flow rates in small pipes, which makes them unsuitable in all circumstances. 

Selecting an accurate flowmeter is crucial for obtaining precise readings in fluid systems. At times, it may be better to combine the various forms of flowmeters in order to glean the best possible results.

WEIBAO offers electromagnetic and ultrasonic gas flow meter that assist end users in identifying solutions for measuring liquids. All of the above are accompanied by our experts who can assist you when selecting the right flowmeter, installing and maintaining it so you can be sure your measurements are accurate and reliable. We want to ensure that you receive the most optimal technology for all your fluid measurements.