Many parts of our water networks are several decades old – a hundred years or more in some cases. As pipes are typically buried, it is challenging to inspect them. Without active monitoring, leakages can go undetected for years. Flowmeters are a game-changing technology. The more accurate the measurement, the better even relatively small leakages can be identified – meaning they can be addressed before they develop into a serious problem. Flowmeters can be installed on pipes with diameters from a few millimeters up to three meters and even more.

There are several different types of flowmeters, each using a different principles of physics, and each typically best suited to a different application. Process industries, for example, use vortex or Coriolis flow meters, depending on the fluid being monitored. Each of these technologies uses a physical property of flowing fluid and turns it into a measurement. The flowmeters most used in the water industry make use of the fact that water conducts electricity, and that anything that conducts electricity also responds to electromagnetism.

The basic principle here is that in water, especially if it contains dissolved minerals, some of the molecules break up into ions – or smaller molecules that have either a positive or a negative electrical charge. It is these ions that are responsible for the conductivity of water. A magnetic field is applied across the water flow. As the ions flow through the magnetic field, an effect similar to that of a dynamo occurs, with a small electric voltage being induced across the pipe. Electrodes pick up this voltage and feed it to the electronics of the flowmeter, where the electrical signal is measured and used to calculate the speed of flow of the water.

These measurements can then be aggregated from across the water network and used to detect leakages.

ABB’s flowmeters are at work across the globe, making a contribution to better water management and less waste, helping the water industry outrun, leaner and cleaner.