Level sensors for level measurement

Levels must be measured in almost all industries. Depending on the application, you want to continuously measure the level or occasionally receive a notification that states the quantity or volume: is there enough liquid in the tank? Is the silo sufficiently solid?

Level switches and level sensors

Level sensors and level switches provide information about the level of substances present in tanks, silos and other liquid containers. A distinction is made between continuous level measurement (analog) and level detection of minimum and maximum levels.

Analogue level measurement

Sensors for continuous level measurement provide constant information about the level of the substance present (level sensors). Level detection sensors provide information on predefined levels when not measuring any arbitrary level. Something that is the case with continuous level measurement (level switches). Level detection sensors are ideal for detecting minimum and maximum levels, leak detection and overfill protection.


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Level sensors for level measurement KFX - Rechner Sensors - SensoPart

Level sensors for level detection

Level sensors offer the solution to continuously measure the level of the dust present in tanks and silos. Think of level measurement of liquids, bulk goods, pastes, powders and solids. The level is converted into an analog signal using level sensors. This signal can be displayed directly on the sensor or incorporated into a process control system.

Min-max level detection

By detecting a min-max level in a silo, a pump control can be performed by applying two level sensors. One level sensor for the minimum level and one for the maximum level. When the level reaches the minimum point, the digital output switches the filling system of new liquid. As soon as the tank reaches the maximum level, the supply stops. This not only prevents malfunctions in the process, for example when a storage tank becomes empty or a pan boils dry, but also prevents production loss and damage due to the overflow of a storage tank or reservoir.

Measuring principles for level measurement: 

  • Capacitive level measurement
  • Ultrasonic level measurement
  • Runtime measurement with laser (TOF principle)


Solids    Transparant       Not transparent  
Sticky fabrics and foam
   Capacitive level measurement
Yes Depending on material Yes Yes Yes
   Ultrasonic level measurement Yes Yes Yes Yes No
   Runtime measurement with laser (TOF-principle) Yes Yes No Yes No

Capacitive level sensor for analogue level measurement

Capacitive level sensors continuously measure the level of the liquid present. The KFX TrueLevel capacitive level sensor from Rechner Sensors features a probe and is set with an empty silo, tank or container that provides a linear analog output signal over the entire fill range of any medium in 4-20 mA or 0-10 V DC. The probe has a maximum length of 2 meters.

Integrated electronics

All electronics of the capacitive level sensor are integrated in the G1 "mounting head. Due to the patented three-electrode concept, each sensor has a reference area for compensating the different liquids (even at low values such as ≥ Ɛr 1.2). So there is only one setting required to commission a new level sensor.

Rechner's TrueLevel KFX level sensor is ideal for applications where different liquids are processed with one machine. Read more about capative sensors.


Read more about the KFX TrueLevel level sensor

Capacitive level sensor for analogue level measurement - Rechner Sensors

Analogue capacitive level sensor with Probe - Integrated logic - KF0644 - Rechner Sensors

Capacitive sensor for level measurement of adhensive and viscous substances

The LevelMaster sensors from Rechner Sensors have been developed for level measurement of liquid and viscous substances that are adhesive and / or conductive. The 26-series capacitive sensors from Rechner Sensors are High Performance (HP) sensors with unique characteristics in size and shape of the sensor.

26 series capacitive level sensors

The 26 Series sensors perform better than any sensor when it comes to ignoring material build-up. With no moving parts, the 26 Series sensor differs from other level sensors such as: vibrating rods, tuning forks and paddle wheels that are prone to cavitation, bridging and material buildup jamming. The 26 series has two models: 1 model for high dielectric materials (such as ketchup and bread batter) and 1 model for everything else (eg grains, flour and alcohol products).

Detecting contamination

In addition to the new analogue output option, it is also possible to detect signs of contamination so that a cleaning process can be initiated. Another application option is a representation of the change in the dielectric constant (DC) of the product to be monitored for quality control. For quality control purposes, the empirically determined starting values ​​can be checked and analyzed using, for example, a PLC. Read more about analogue sensor for level measurement.

Analogue sensor for level measurement of adhesive, and syrupy substances - Rechner Sensors

Level control of conductive liquids, pastes or syrups - Rechner KS 700 KS 800

Continuous level measurement of solids and liquids with ultrasonic level sensor

Ultrasonic level sensors offer the solution for level measurement of objects or substances with uneven surfaces or under difficult environmental conditions or highly reflective liquid surfaces. A major advantage of ultrasonic sensors is the absolutely reliable suppression of the background by the 'time-of-flight' principle.

Ultrasonic level measurement

The level measurement is not affected by the dielectric constant, density or humidity. Typical for ultrasonic level sensors: continuous, contactless and maintenance-free level measurement of liquids, pastes, sludge and powdery, but also coarse, bulk materials. The accuracy and performance of ultrasonic level sensors decrease in foaming and vacuum applications. Read more about ultrasonic sensors

Continuous level measurement of solids and liquids with ultrasonic level sensor
Level detection with runtime measurement - Rechner Sensors

Level detection with runtime measurement

Laser sensors that determine the level in tanks and silos based on a light-travel time measurement are ideally suited for level measurement of non-transparent liquids, bulk solids and varying materials. In addition, they are less suitable for the detection of foaming, sticky and transparent liquids. These substances cause dispersion and lens contamination, which significantly reduces the reliability of the measurement. SensoPart's F 55 series photocells are ideal for level control. Control of two filling levels with two switching outputs can be set independently.

Features level detection with smooth-running time measurement:

  • Contactless level measurement
  • Suitable for bulk goods, solids and powders
  • Not suitable for sticky, foaming and transparent liquids

Capacitive level measurement of additives

3D printers use powders and plastics that are processed into a rapid prototype. Accurate detection and level measurement of the additives is of great importance. Both for machines to function optimally, but also to get the desired end result.

Detect powder or liquid level

But how do you know what the powder or liquid level is in the printer or the additive? Rechner Sensors has the solution with capacitive level sensors that can excellently detect the conductive powders and sticky liquids. Read more about level measurement of additives for 3D printers.

Capacitive level measurement of additives - Rechner Sensors
Level control with sensor for minimum and maximum level - SensoPart

Level control with sensor for minimum and maximum level

Peanuts are supplied from a silo and placed in the packaging. A TOF sensor checks the filling level in the packaging by means of time-of-flight measurement. The level sensor switches at a minimum or maximum level.

Time of Flight sensor

The principle of time of flight (Time of Flight) allows for the reliable detection of objects of different colours on surfaces up to 5 meters. Thanks to two switching outputs, one sensor can monitor both the maximum and minimum levels. Read more about F 55-sensors.

F 55 - Lichtlooptijdmeting voor lange afstanden - Time of Flight for long distance - SensoPart