Salt sensor for monitoring of softener and protecting downstream R.O. units

Salt sensor with ultrasonic sensor

Field of application
Function of the sensor

Technical data
Example of use

Field of Application

To prevent membrane problems either dosing units for stabilizing the water or softener units that change hardness component to harmless salts are installed. Otherwise lime and other precipitates will scale the membranes and causes high costs. 

There are two possibilities to control the feed water stream to the reverse osmosis unit:

  • Salt Sensor
  • Rest Hardness Control Unit

Function of the Sensor
The ultrasonic sensor is build in the top cover of the salt tank of a softener unit. The sensor is calibrated at low level of the salt. Afterwards the brine tank is filled up with tablet salt. If the level of salt is reduced until the minimum the salt sensor unit gives alarm and shuts off the connected reverse osmosis unit.

Technical Data

measuring system
ultra sonic
voltage of sensor 20...30 VDC
range of operation 3...81 cm
accuracy 1 mm
lateral distance to wall of salt reservoir min. 3 cm
lenght of cable 2 m
max. load of output 150 mA NC
learing function yes - volatile
display 1 LED at upper side of sensor
lengths of sensor 52 mm
thread of sensor M18 x 1
dimensions of control box 190 x 120 x 80 mm
max. load of relay output 500 W
electrical connection 230 V, 50 Hz


Example of use

HP2 High Pressure 100 with rest hardness control and salt sensor