Flow meters are devices used to measure the flow of a liquid or gas. They can be used in industrial and commercial applications, as well as the home.

There are many types of flowmeters for water available on the market, each with different features. This guide will walk you through four common types of flow meters: velocity, differential pressure (DP), positive displacement (PD) and open channel (OC).

Velocity Flow Measurement

Flow is the measurement of how much fluid passes through a given point in a given amount of time. It’s important to understand the different types of flow meter because the type you choose for your application will have an impact on your costs, performance and accuracy.

Flow meters measure how much water flows past a point in a certain period of time (e.g., one second). In order to calculate the volume of water flowing through that point, you must know both its velocity and viscosity (the resistance to movement).

Differential Pressure Measurement

• Differential pressure flow meters measure the difference in pressure between two points. The measurement is made by comparing the pressure between the two points, and a transmitter translates this difference into a readable value on an LCD screen.
• Commonly used for measuring liquids and gases, differential pressure flow meters use a diaphragm or bellows to measure fluid movement through a pipe or tube.

These flow meters are best suited for measuring turbulent flows, and they’re used in applications such as:

 -Monitoring fluid velocity in pipes or tubes

-Determining how much liquid is flowing through a pipe or tube

 -Measuring the pressure drop across a restriction

Positive Displacement Flow Measurement

This type of flow meter uses a piston to measure the volume of liquid that passes through it. The most common type, the rotameter, is an example of this style. Rotameters can be used for both liquids and gases and are often used for low-flow applications.

They are classified as positive displacement meters because they use a piston to measure liquid flow instead of relying on some other method (like ultrasonic waves). This makes them quite versatile; they can be used for any application that requires accurate measurement at low rates or high pressure.

Rotameters are commonly used for flow measurement in process industries such as chemical plants and power plants. They are also commonly used in industrial settings where there is a need to measure the amount of liquid that passes through pipes or tubes.

Open Channel Flow Measurement

Open channel flow measurement uses a pressure sensor to measure the difference in water levels. The pressure sensor measures the difference in water levels and converts it to a flow rate.

The following is an open channel flow meter with a differential pressure transducer that outputs an analog signal proportional to the voltage measured across the two ports of its differential arrangement.

The pressure transducer is connected to a measuring device, which converts the analog signal into flow rate. The measuring device can be an electronic meter or a flow computer that calculates the flow rate based on the inputted data.

Conclusion

There are many different flow meters available, but they all serve the same general purpose. They measure the amount of fluid that passes through them and give you a reading based on this information.