Piezoelectric Drives in Point Level Switches

Industries that use tanks or storage silos—such as agriculture, coal, cement, breweries and many others—need a way to monitor the level of material that is in storage. If the level of material drops below, or rises above normal levels, potential problems could arise in the industrial processes.

Point level switches are useful to monitor levels and keep them within normal ranges. But how do these switches work? They use piezoelectric motors.

What is A Piezoelectric Motor?

Piezoelectric motors (or piezo motors) are simply electric motors that run due to a piezoelectric material that changes shape when electrical fields are applied. The piezo material generates vibrations which allow the motor to translate the motion into either linear or rotary movement.

The motions of these motors are used in point monitors to determine the level of material inside a storage silo or tank. Vibronic switches function using the same process, but can activate drains or pumps to regulate the level of material in the silo or tank.

Let’s take a look at how point monitors and vibronic switches work:

How Point Monitors Work

In point monitors, a piezo motor is integrated into the monitor unit. This motor causes the rod attached to the monitor to vibrate at a specific frequency. The frequency is known due to the properties of the motor, and is monitored by a frequency sensor inside the monitor’s hardware.

When the rod is covered by a medium, such as liquid, grain, or other material, it vibrates at a different frequency than when exposed to air. Electronics compare the amplitude of the vibrations to the known value and inform a user whether the rod is exposed or covered by the medium.

Control and signaling systems can also be connected to the point monitor in order to activate automated processes that can rectify high or low levels of the stored medium.

Endress+Hauser Point Switches

Endress+Hauser offers a number of vibronic switchesfor different applications. Our products will ensure that you can find a point level switch to meet your application’s needs.

Some of our products include:

  • Soliphant T FTM20 / FTM21 – These point level switches are used in silos which contain fine or coarse-grained, non-fluidized bulk solids. It has a diverse array of applications and probe lengths.
  • Liquiphant T FTL33 – For use in all liquids, the Liquiphant FTL33 is best used in storage tanks, mixing vessels and pipes. The FTL33 meets stringent hygienic requirements and has a highly reliable switching function to ensure proper operation.
  • Liquiphant T FTL31 – This unit is used in liquid tanks, vessels and pipes. It can be used for overfill prevention, or to protect the pumps in cleaning or filtration systems. It can also be utilized in cooling and lubrication vessels. The FTL31 can be installed in areas where buildup, conductivity and other conditions make the area unsuitable for other switches
Have a question? We can help.
Have a question? We can help.

Topics: level switches, level measurement


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