Veratron Capacitive Level Sensors


When installing the Capacitive Tank Level Sensors, it can occur that one does not immediately receive the expected measurement values.

Follow the instructions of this document to avoid the most common mistakes.


This article applies to the following sensors:



ARTICLE NO.                 

LENGTH [mm]     

Fresh Water


80 - 600

Fresh Water


600 - 1200

Fresh Water


1200 - 1500

Fresh Water


80 - 600

Waste Water


200 - 600

Waste Water


600 - 1200

Waste Water


1200 - 1500




The first step should be to check the wiring of your installation.

Mistakes often occur because the different sensor types must be connected in different ways, and there are also changes on the wiring depending on the instrument that’s supposed to interpret the output.


There is a separate post about the correct wiring for all different installations:

Connecting Capacitive Level Sensors



It is possible to test the correct functionality of the sensor, by using a multimeter to measure the output current delivered by the sensor.
The multimeter must be set for mA measurements and the leads must be connected accordingly (refer to the manual of the multimeter manufacturer for more details).

Build your test setup according to the following schematics. (check for the correct sensor type)



Sensors N02-240-40x

Test circuit - N02-240-40x


Sensor N02-240-802
Test circuit - N02-240-802


Sensors N02-240-90x 

Make sure, the switch is in the position pointing towards the center of the sensor.

Test circuit - N02-240-90x


When setting up the circuit as described above, the reading should be around 4.0 mA. (With sensor completely out of the water)
Dip the sensor in the tank and check the output current on the multimeter.
The current must increase when the water level is rising and decrease when the level is lowered.
Standard Veratron instruments (e.g. ViewLine) are calibrated to read a signal in the range of 4 mA (empty tank) to 20 mA (full tank).
To calibrate the sensor, dip it fully into water and then turn the little screw on the potentiometer until the value reaches 20mA.