What Is a Digital Flow Meter?

A digital flow meter is a type of sensor that is used to determine the amount of fluid that moves through a tube. The most basic flow meter uses mechanical gears that move when fluid begins to flow. Digital flow meters, by contrast, do not use moving parts to collect and display information about the flow of fluid. This lack of moving parts allows a digital flow meter to be more accurate and durable than a traditional flow meter.

Flow meters can be used in a wide variety of applications and with many types of fluid. The fluid being measured can be a liquid such as water or a gas such as air. Digital flow meters are common in both commercial and scientific fields. A restaurant or bar, for example, might use a flow meter to track the daily amount of a certain beverage being dispensed, and a laboratory might use a flow meter to carefully measure the level of gas for an experiment.

Several methods are used by digital flow meters to determine how much fluid moves past the sensor. One common variation is the digital magnetic flow meter, also known as a mag flow meter. A mag flow meter uses two magnetic coils placed on opposite sides of a tube. When fluid moves through the tube, the flow interacts with the magnetic field and creates voltage. The level of voltage is measured digitally and corresponds with the rate of flow inside the pipe.

Another type of digital flow meter uses ultrasonics to determine the rate of flow. Two ultrasonic transducers are located on opposing sides of a tube, facing each other. One of these transducers produces an ultrasonic pulse, which is detected by the opposite transducer. Fluid flowing within the tube causes the ultrasonic sound waves to change speed. By digitally measuring the time it takes for an ultrasonic pulse to be received, the amount of fluid moving through the pipe can be calculated.

Digital flow meters can interpret data in multiple ways. Basic meters simply display the flow information on a digital readout, which can be read by operators. More advanced digital flow meters can be interfaced with other pieces of hardware. In an automated facility, for instance, a digital flow meter might be directly linked to a valve, which can limit or increase the flow rate depending on the data. Digital flow meter information can also be logged for review by operators at a later time.