For the most part, flowmeters are used to infer mass flow through calculations that flowmeters and flow monitor instruments make after taking various flow measurements, such as absolute pressure, differential pressure, viscosity, and temperature.
Most flowmeters are made of three parts: the primary device, transducer, and transmitter. These three flowmeters parts are usually combined so that the flow meter is one complete instrument. Flow indicators, which are observation windows in industrial processing lines, aid in measuring flow by visual indicators.
Flowmeters are useful in a variety of fields. Medically, flowmeters are can be used measure a patient’s air intake. In plumbing, flowmeters are used to measure the amount of fluid running through a tube for efficiency purposes. In general, flowmeters are used in many industrial applications for flow measurements to help companies determine profit gain or loss. Other industries that benefit from the use of flowmeters include automotive, petroleum and gas, utility services, HVAC, food processing, and raw materials.
Flowmeter manufacturers offer various instruments for different measurements of flow.
Thermal mass flow meters take measurements with two sensors that work together. A temperature sensor reference and an active heated sensor take measurements by calculating how much heat loss occurs in the flowing liquid, and thus these flowmeters can determine the flow rate based on this amount.
Another type of flowmeter is the Coriolis mass flow meter, which operates on the basis of the Coriolis Effect. In the Coriolis Effect, an excitation force is applied to the flowmeter tube, causing the fluid or gas to rotate because the acceleration is acting in opposite directions on both sides of the applied force. A flowmeter measurement can then be taken.
Other kinds of flowmeters operate using sound. These are called ultrasonic flowmeters, and include several types, like Doppler Effect flow meters and time-of-flight flowmeters.
Each type of flowmeter has specific guidelines that must be followed for proper use. For example, when using gas flowmeters, the flowmeters must remain full of gas. Liquid in gas flowmeters can affect the flowmeter’s accuracy. Similarly, in order for liquid flowmeters to work properly, they must remain full of liquid. Gas in liquid flowmeters can affect the accuracy of the flow meter’s readings, as can contaminants of any kind.