MK108 as sensor for automation

Hi!

I am using a GSM RTU 5011 (Mobile GSM based alarm controller unit with inputs and outputs) for controlling and sensing stuff in my sailingboat. I need a sensor that will lay a input to ground if there is water in the boat. This will trigger as SMS to be sent to me, and an output will be activated starting a pump.

I was wondering if this MK108 circuit mabe could be used directly on a “NC/NO dry contact” input? The input triggers if the input is connected to ground.

If yes, some questions:

  1. I asume I just de-isolate two wires and mount them so both touch surface when I want the alarm to go off?
  2. How small/large distance sould they have between them?
  3. Will it work with bouth fresh and salt water?
  4. Will it trigger on diesel or/and Oil?

Looking forward to hear from you!:slight_smile:

Best Regards,
Anders Hauge
Norway

The MK108 also triggers the sounder by pulling to ground when water is detected. You should try to be sure.
Perhaps you can use the whole circuit on the 5 Volts so the sounder stays in the circuit. Can compensate for leaking currents which may trigger your alarm? Experiment.

Perfectly clean water H2O does not conduct but as almost all normal water contains impurities it can work with normal water.

Normally diesel and oil don’t conduct also.