# What is water flow meter? And how does water flow meter work?

The amount of water flowing through a pipe is measured using a water flow meter. Depending on the application for water being measured, the required level of maintenance, and the available budget, there are various water flow meter technologies to pick from. Each of these water flow meter types have a different operating principle, offer advantages for a particular application, and have an overall cost of ownership. So, which water flow meter is best for your application involving water flow measurement?
Ultrasonic flow meters, magnetic flow meters, mechanical water flow meters and vortex volumetric flow meters are some of the important types of water flow meters.

### Ultrasonic Flowmeter for Water Industry

Ultrasonic water flow meters use ultrasound to gauge a fluid velocity as it travels through a pipe in order to calculate volumetric flow. An ultrasonic signal is transmitted in the direction of the flowing fluid downstream in a transit-time ultrasonic liquid flow meter, followed by an ultrasonic signal that is transmitted against the running fluid upstream. In its simplest form, the time taken for the acoustic pulse to reach upstream and downstream is calculated. The fluid flow velocity is then determined using this differential time. The volumetric flow rate in the pipe is then calculated by the meter using this fluid velocity. Clamp-on ultrasonic meters offer a wide range of applications and are particularly suitable for measuring water flow in big pipes. Insertion type ultrasonic flow meters are useful where it is not possible to stop the flow in the pipeline. Hot tapping is possible for such meters. This saves a lot of time and money wasted, as the sensors are installed in the running pipeline.

### Magnetic Flowmeter for Water Industry

To measure volumetric flow, magnetic flow meters employ a magnetic field to gauge the flow rate of a fluid in a pipe. Faraday’s Law of Electromagnetic Induction is applied here. Faraday’s Law states that as liquid moves through a magnetic field, voltage is produced. Electronics convert the voltage signal into the volumetric flow rate based on how much voltage is generated when the water moves. Due to their inability to monitor ions in pure water and inability to measure flow of hydrocarbons, magnetic flow meters are not appropriate for custody transfer applications.

### Vortex Flow Meter used for Water Industry

Water flow meters that utilise vortices, do so by using a sensor submerged in the flow. A barrier, such as a boulder in a stream or a flagpole, causes a fluid to “swirl” and create vortices, which are natural forces. Each vortex that passes through a vortex meter causes a sensor tab to flex, which results in a frequency output that is inversely proportional to the volumetric flow rate. Recalibration of the transmitter needs to be done in a flow calibration lab, which is an expensive and time-consuming. Therefore, other types of flow meters like differential pressure flow meters are preferred by some users.

### Mechanical / Turbine Flow Meters used in Water Treatment

A form of flow meter that uses a system of moving parts to physically measure flow is a mechanical flow meter. The fluid travels either through a spinning turbine or rotor (positive displacement, or PD) or a set of gears or chambers. Electromagnetic and ultrasonic flowmeters are fundamentally different from mechanical flowmeters. Water, fuels, viscous fluids, and other liquid flow rates are conveniently monitored with mechanical flow meters. However, the accuracy of many of these meters are not as good as the other three types of flowmeters mentioned above.

Selecting the best water flow meter depends on the application; different flow meters perform better when measuring various things. You can discover more by watching videos, reading blogs, and using various digital tools. This will help you to narrow down your search for the ideal flowmeter for your liquid and water flow application.

Do you need a flow meter for your application?
Manas Microsystems, an Indian manufacturer of Electromagnetic Flowmeters and Ultrasonic Flowmeters (including clamp-on & insertion type ultrasonic flowmeters), is a leading supplier of variety of Flowmeters in India. These flowmeters work under variety of flow, temperature, fluid quality and line pressure conditions of liquids or gases.