5
1. Theory
The electric resistance depends on the salt content of the water. Distilled water doesn’t conduct the
electric current but salt water does. The measurement of the electric resistance can be used as a
parameter for the salt content of the water - if the composition is known. The conductivity is
determined as µS, or mS (micro- or millisiemens). Typical conductivity values are:
Distilled water
> 30 µS
Fresh water
100 – 1,500 µS
Salt water
45 -49 mS
2. Delivery
The Aqua Medic
LF controller
is supplied with a conductivity probe and ready to use. For control,
it is possible to connect an electric instrument (pump, solenoid valve) at the socket of the main
plug.
Description of the front panel
1. Display
2. Display relay on/off
3. Set/measuring switch
4. Measuring range switch
5. Set point adjustion
6. Calibration mS
7. Calibration µS
8. Electrode, firmly connected
9. 220 V-plug/socket for
pump / solenoid valve
3. Starting/measuring
1. Connect the main plug to 220 V, if not indicated otherwise.
2. Turn switch (3) on “M" (measuring).
3. Immerse the top of the conductivity probe into the test liquid, minimum depth 4 cm.
4. Switch the measuring range switch to the right range (µS for pure and fresh water, mS for
brackish and salt water, recalibrate, if necessary).
5. After 3 min. you can read the value.
4. Controlling
1. Switch knob 3 (set/measuring) to „set“. Adjust the desired set point at knob 5 (set point
adjustion).
2. Turn switch 3 back to „µS“. The unit is now ready to use. As soon as the adjusted set point is
exceeded, the unit activates the socket at the main plug.