A flow meter, also known as a flow gauge or flow sensor, is a device used to measure the flow rate of fluids such as gases, liquids, or steam passing through a pipeline, expressed in terms of quantity per unit of time. Let’s start our article by briefly explaining what a flow meter is. A flow meter measures these flows either mechanically or electronically. In another definition, a flow meter is a type of device used to measure the volume or mass of a gas or liquid. Depending on the industry, flow measuring devices can be referred to by different names such as flow gauge, flow indicator, liquid meter, or flow rate sensor. All these terms fall under the general category of flow meters.
For example, open channels can be measured using flow meters, and they can also be used to measure the flow of liquids and gases in pipes. To answer the question “What is a flow meter used for?”, we can say that it is used to maximize the precision, accuracy, and resolution of liquid flow measurement. One of the main benefits of a flow meter is that it ensures maximum resolution in liquid measurement.
Flow meters come in various designs. Some are installed directly inside the pipe for in-line measurement, while others perform measurements externally, depending on their design and functionality. Flow meters that measure the flow rate of solids, liquids, or gases are commonly used in devices such as engines, compressors, pumps, or heat exchangers. They are used both to verify manufacturing accuracy and to evaluate product performance. When we look at where flow meters are used, we see that they are most commonly utilized by mechanical engineers. ###
What are the units of flow measurement?
As mentioned earlier, a flow meter is a device used to measure the amount of fluid—gas, liquid, or steam—passing through a system, expressed in quantity per unit of time. Flow meters have specific measurement units, which can be expressed as follows:
- Liters per second (L/s)
- Liters per minute (L/min)
- Liters per hour (L/h)
- Cubic meters per minute (m³/min)
- Cubic meters per hour (m³/h)
- Kilograms per hour (kg/h)
- Kilograms per minute (kg/min)
What are the types of flow meters?
Flow meters, which allow for instantaneous and total flow measurement and data evaluation, are essential components of automation systems. There isn’t a single definitive answer to how a flow meter works, as there are different types designed for various applications and needs. The first step is to determine your specific requirement. By selecting the appropriate flow meter, you can ensure maximum efficiency. Therefore, it’s important to thoroughly review the different types before purchasing a flow meter and choose the one that best suits your needs. Flow meter prices vary depending on the device’s features.
Here are some common types of flow meters:
Electromagnetic Flow Meter
Electromagnetic flow meters are among the most technologically advanced types. They are used to measure the flow of conductive liquids and operate based on Faraday’s Law of Electromagnetic Induction.
Ultrasonic Flow Meter
An ultrasonic flow meter measures the velocity, flow rate, and direction of fluid within a pipe without causing any damage to the pipe or the fluid. It uses sound waves to determine the velocity and quantity of the flowing liquid. Ultrasonic waves are transmitted and received, allowing accurate measurement.
Turbine Flow Meter
Turbine flow meters are widely used in water treatment and spring water production facilities. They are also used in swimming pools and liquid filling machines to measure high-pressure and high-temperature liquids. They are easy to install and require minimal maintenance.
Positive Displacement Flow Meter
Positive displacement flow meters are ideal for measuring the flow of viscous fluids that do not flow easily, such as glue, syrup, hydraulic oils, grease, paint, or additives. They are the most suitable type of flow meter for “thick” or high-viscosity liquids.
Float Flow Meter
Float flow meters are commonly used to measure the flow rate of water. In addition to water, there are also types designed for measuring air flow.
Flow Control Valve Flow Meter
Flow meters with control valves operate mechanically and are used to regulate gas flow rates. They are among the preferred types of flow meters for gas measurement and control applications.