The previous section discussed differential flowmeter and mechanical flowmeters. Both of those had the disadvantage of moving parts that could wear out. Electronic flowmeters get around this problem by not having moving parts. The other disadvantage of the flowmeters in the previous section was the effect on the downstream flow while most electronic flowmeters have no effect on the flow.

Electronic flowmeters work in a number of ways. The main types of electronic flowmeters are magnetic flowmeters, vortex flowmeters and ultrasonic flowmeters. Each type has their own use, advantages and disadvantages.

The magnetic flowmeters require that the fluid being measured is conductive. The fluid is passed through a flow tube that is non-magnetic and has an insulated lining and a pair of electrodes that are inserted at each end. Air or gas bubbles should be removed upstream and some fluids can cause a build up of substance on the lining that can damage the device or affect its accuracy.

Vortex flowmeters have been used since the early 70s and are considered an alternative to differential pressure flowmeters because they have less of an effect on the flow. These are economical and used widely across many industries and can even measure steam. Vortex meters are not suitable for applications with an intermittent flow or where the fluid can cause a build up on the lining of the flowmeter.

Ultrasonic flowmeters measure either the transit time or frequency shift of ultrasonic waves in a specially designed acoustic field. There are both inline and clamp on styles for use in different applications. The clamp on style are more portable, have no effect of the flow rate or pressure and can be used on existing pipes. These have a higher set up cost but are lower in cost to maintain, last longer than mechanical types and wider range of applications.

Mass flowmeters measure flow rate of a gas or liquid in units of mass such as pounds per minutes. Most commonly used types of mass flowmeters are thermal flowmeters and coriolis flowmeters. Both of these types of flowmeter are very accurate, have a broad range of uses but are more costly to set up.

This article is only a basic primer of flowmeters and intended to help the reader narrow their focus to a specific type or specific flow measurement technology. You can search for more detailed information on a specific type of flowmeter, follow links from our site to other articles or use your favorite search engine to find out more.