Level Sensors

A simple level sensor relying on a float to send a signal or trigger a switch if a certain level is reached. The switch and wiring are typically attached to the float. This type of sensor can also be deployed as a multiple or in an array to get multiple different level reads. They are inexpensive but prone to failure if debris gets caught in the float. Attention to the liquid media is important when choosing this type of level sensor. Output is a switch or voltage signal that triggers if the set (mechanical) level is reached.

Magnetic level sensors also rely on a float but don’t have the electrical wiring attached to the float resulting in less chance of tangling or being disable by debris. A magnetic sensor is typically installed on the outside of the tank, making it easier to service. Output is a switch or voltage signal that triggers if the set (mechanical) level is reached.

Conductive sensors can measure the presence of liquids by allowing a small electrical current to flow across electrodes if a conductive liquid covers the electrodes. These types of sensors are ideal for leak detection. Output is a switch or voltage signal that triggers if the sensor is submerged.

This sensor is mounted above the higher liquid level and sends periodically an ultrasound signal down to the liquid level surface where it gets reflected and sent back to the sensor. A circuit called ToF (Time of Flight) measures the time it takes for the sound to come back and calculates the distance. Subtracting this distance from the overall depth of the tank or enclosure will result in a level measurement. Ultrasound level sensors are very reliable, relatively inexpensive and have excellent accuracy. Since they are contactless, debris is not an issue and maintenance, and calibration are simple. Unless you have some specific needs, this is your go-to level sensor. Output is typically a 4-20 mA or serial communication.