Understanding How Liquid Level Sensors Work

The level of liquids or bulk chemicals in tanks or other containers is measured using liquid level sensors. The ideal solution will depend on the particular application and the characteristics of the liquid or chemical being monitored. There are various types of tank level sensors, each with its own benefits and drawbacks. Typical tank level sensor types include:

Submersible level sensors: These sensors are made to be submerged in the liquid or chemical in the tank.  They function by gauging the liquid or chemical pressure at the tank’s bottom. The pressure at the tank’s bottom will change as the liquid or chemical level does, and the sensor will monitor this change to calculate the level. The level of a variety of liquids and chemicals, including some that are caustic or abrasive, can be determined with submersible level sensors.

Ultrasonic level sensors: These sensors measure the level of a liquid or chemical in a tank using sound waves. They operate by sending out a sound wave, which travels to the liquid or chemical’s surface, and then bounces back to the sensor. To estimate the level, the sensor calculates the separation between itself and the liquid or chemical’s surface. Ultrasonic level sensors are suitable for usage in difficult situations since they are non-contact and can be detected through solid and opaque materials.

Radar level sensors: These sensors measure the level of a liquid or chemical in a tank using microwaves. They operate by sending out a microwave signal, which travels to the liquid or chemical’s surface, and then bounces back to the sensor. To estimate the level, the sensor calculates the separation between itself and the liquid or chemical’s surface. Radar level sensors are suitable for usage in high temperatures and pressures since they are non-contact and can be detected through solid and opaque materials.

Capacitance level sensors: These sensors measure the level in the tank by using the electrical capacitance of the liquid or chemical. By generating an electric field between two electrodes and acting as a dielectric material, the liquid or chemical changes the capacitance between the electrodes. The sensor then determines the level of the liquid or chemical based on the change in capacitance. The liquid or chemical must come into touch with the capacitance level sensor because they are contact devices.

Level sensors with a vibrating fork: These sensors employ a vibrating fork to measure the liquid or chemical level in the tank. They operate by causing a fork-shaped probe to vibrate at a particular frequency; when the probe makes contact with the liquid or chemical’s surface, the vibration changes, revealing the level. Vibrating fork level sensors are contact devices that need a liquid or chemical in close proximity to the sensor in order to function.

Optical level sensors: These sensors measure the level of the liquid or chemical in the tank using a laser or infrared beam. They operate by emitting a laser beam and measuring the light’s reflection off the surface of the liquid or chemical. To estimate the level, the sensor calculates the separation between itself and the liquid or chemical’s surface. Optical level sensors are suitable for usage in difficult situations since they are non-contact and can be detected through solid and opaque materials.

Float level sensors: These sensors measure the level of a liquid or chemical in a tank using the buoyancy force of a float. They function by suspending a float inside the tank on a cable or rod; as the liquid or chemical level changes, the float will rise or fall, showing the level. Float level sensors need a liquid or chemical to be in contact with them because they are contact devices.

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