Flow meter is an instrument used in measuring the flow of a gas or liquid through a pipe. This device can give the flow rate in one among the measurement values such as mass flow and volumetric flow. If the device gives the measurement in volumetric flow perspective then the results is in liters, cubic inches or gallons per second. If the device gives measurements in mass flow, the results will come in pounds or kilograms per second. These measurement ways depend on the kind of geographical location and industry. The flow meter is classified under the following categories. Mechanical flow meters measure the rate of flow according to the movement of set of impellers, helical blades and paddles. Pressure flowmeters is another category in which the flow meters calculate the rate of flow as per the pressure differentials calculated using orifice plates, venturis and pilot tubes.
Optical flow meters measure the dispersed light to calculate the flow rate of liquid or gas by using the photo detectors and lasers. Thermal flowmeters is another category under which the flow meters extrapolate the values of flow rates as per the pre-determined knowledge about the characteristics of material in tandem with measurement of flowing and static temperature differentials using temperature sensors and heater elements. Flow meters present in the manufacturing industrial areas perform as control mechanism. It is also applied in the domestic sectors to measure the consumption of water or gas for billing. The selection of flow meter by people depends on their purpose of using the flow meter. Some of the common types of flow meter are water meters, batch meters, electromagnetic flow meters, medical gas flowmeters and insertion meters. People who like to use flowmeter in their industry have to consult an expert before they install it for any of their industrial application.