Process control in many industrial applications uses devices like a flow meter for measuring the flow rate of gas or liquid. The measurement is represented either in volume or mass. Flow meters have a wide variety of applications. In medicine, you can use a peak flow meter to measure a person’s lung capacity.
But flow meters are more widely applied in manufacturing, industrial, and utility industrial applications like water management.
How are flow meters classified?
In general, a flow meter is classified according to its principle of operation. For example, a mass flow meter is called such because it measures a fluid’s movement in mass.
- Coriolis flow meter. This type of flow meter makes use of the Coriolis Effect to measure fluid mass as it flows through two pipes or tubes that are vibrating. The premise of this set-up is that by taking the wave pattern changes in the tubes, you can get a correlation to the fluid flow rate as it passes through.
- Ultrasonic flow meters. This flow meter uses the shift in sound waves to measure flow rate. Two waves coming from different directions set off at the same time. The separate measurement of these two waves represents the fluid’s flow rate. Various constants relating to the elements surrounding the fluid also impact the measurement.
- Doppler shift flow meter. To measure flow rate, a Doppler shift flow meter uses the change in amplitude and frequency of sound waves bouncing off particulates present in the liquid.
- Variable area flow meter. This type of flow meter is considered to be a standard flow meter and is used in many applications. It consists of a calibrated tube with a float inside. The float moves by force as the fluid passes through the tube and the location of the float about the calibration represents the flow measurement.
Each type of flow meter is suitable for specific applications. Understanding the advantages and disadvantages of each type of flow meter can help distinguish which option is best for the use at hand.
How to choose the right flow meter
Industrial and process applications rely on precise parameters to make sure that there are no errors; therefore, it is crucial to select flow meters with these parameters in mind.
- The orientation of flow measurement. Extensive planning helps engineers to determine a suitable flow meter for the application. For example, they need to examine whether the flow rate should be continuous. They also need to determine whether the measurement will be remotely or locally recorded.
- Characteristics of fluid flow. Fluid flow has many features such as pressure, viscosity, temperature, and density. All these characteristics have a significant impact on the measurement results. Therefore, it is vital to choose a flow meter while taking all these characteristics into account.
- Installation area and piping. This pertains to the piping direction, size, material, accessibility, orientation, and valves. The engineer must also know if there are factors that may affect the flow of water through these pipes such as a magnetic field.
These are only a few of the parameters examined before choosing a flow meter for industrial applications. As such, process engineers need detailed information on the nature of the installation to find the exact type of flow meter required.