Thermal Mass Flowmeters - The rate of heat absorbed by a flow stream is directly proportional to its mass flow. As molecules of a moving gas come into contact with a heat source, they absorb heat and thereby cool the source. At increased flow rates, more molecules come into contact with the heat source, absorbing even more heat. The amount of heat dissipated from the heat source in this manner is proportional to the number of molecules of a particular gas (its mass), the thermal characteristics of the gas, and its flow characteristics.

Coriolis Mass Flowmeter - This meter uses the Coriolis effect to measure the amount of mass moving through the element. The substance to be measured runs through a U-shaped tube that is caused to vibrate in a perpendicular direction to the flow. Fluid forces running through the tube interact with the vibration, causing it to twist. The greater the angle of the twist, the greater the flow

Positive Displacement (PD) - PD flowmeters measure the volumetric flow rate of a liquid or gas by separating the flow stream into known volumes and counting them over time. Vanes, gears, pistons, or diaphragms are used to separate the fluid. PD flowmeters provide good to excellent accuracy and are one of only a few technologies that can be used to measure viscous liquids.

An obstruction in a pipe creates vortices on the downstream side of the obstruction. Temperature or pressure sensors measure the vortices to gauge the strength of flow.

Multiphase Flow meters - measures accurately the flow rates of oil, gas and water in oil wells without separation, mixing or moving parts. These are probably the most advanced type of flowmeters in the market and require much expertise in their application and usage

Turbine Flowmeter - As a substance moves through a pipe, it acts on the vanes on a turbine to get it to spin. The rate of spin is measured to find out the speed of the flow.

Calorimetric Principle: Two PTC's (positive temperature coefficient thermistors) reside in the sensing probe tip. One of these monitors the media temperature while the other is heated a % above media temperature. As flow occurs across the sensor, heat is conducted away, proportional to flow speed. This results in a resistance change of the heated PTC providing an output signal.

Compound Flowmeter -A combination of 2 water meters - a large one and a small one, with a special change-over valve.
This compound water meter can handle and measure accurately an extremely broad range of flow rates

Electromagnetic Magnetic Flowmeter - A conductive process fluid is run through a magnetic field. As it creates an electric charge through its interaction with the field, the charge is measured to find the speed of the flow.

Laminar Mass Flow Meter - Alicat flow measurement devices determine the flow rate by accurately measuring the differential pressure in an established laminar flow region passing through a fixed area. This time tested method of flow measurement offers several advantages over most thermal flow measurement devices including shorter response times and greater sensitivity for lower flow rates.

Despite the growing popularity of other flowmeter types, the variable area flowmeter continues to command a major portion of the industrial market. Although it has not enjoyed the same degree of publicity granted more exotic meter forms in technical literature...

Venturi Tube - This differential pressure element actually forces the flow into a smaller diameter section of pipe, then measures the pressure differences between the unrestricted flow and the restricted flow. This element can be used for very accurate measurements if calibrated correctly.