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Water sensor that can sustain submersion, suggestions?

Discussion in 'Datasheets, Manuals or Parts' started by halleffector, May 23, 2016.

  1. halleffector

    halleffector Member

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    I tried using this:

    http://www.dx.com/p/water-sensor-mo...p-depth-of-water-test-red-276572#.V0O2opQvAQ0

    But it started exhibiting symptoms of electrolysis after some days. I'm assuming this product is not designed to be able to sustain continuous submersion.

    I need a sensor like that, a sensor that can sustain powered submersion (months, years at a time) while transmitting data.

    This is for a toy project with an Arduino. I also need a soil sensor that can be submerged in wet soil with similar requirements. But perhaps I should start a different thread for that type of sensor.
     
  2. alec_t

    alec_t Well-Known Member Most Helpful Member

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    If the sensor is DC energised you can expect electrolysis. It's better to use an AC type, e.g. a capacitive one.
    Are you trying to sense the depth of the water, or merely detect its presence at the sensor?
     
  3. halleffector

    halleffector Member

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    Measuring the presence of the water would be sufficient.

    What type of sensor should I look for? Any AC type water sensor?
     
  4. dave

    Dave New Member

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  5. spec

    spec Well-Known Member Most Helpful Member

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    Hy halleffector,

    Of the top of my head, bright stainless steel probes (hygenic) stuck in the ground/water should do the job.

    spec
     
  6. MikeMl

    MikeMl Well-Known Member Most Helpful Member

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    Trick is to use a low amplitude AC (<1Vpp) with no DC component to excite the electrodes. You need to build what is essentially an AC Ohmmeter.
     
  7. halleffector

    halleffector Member

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    I need this for a simple Arduino project, I'd rather not have to make my own sensor. If someone knows of a simple product I can use that would be great.
     
  8. spec

    spec Well-Known Member Most Helpful Member

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    Thx for giving us that information.

    There are quite a few ready made sensors on the market, but so far I have not come across one designed specifically to interface to an Arduino. The sensors are also rather expensive at around the £50UK mark. I have not done an in depth search though.

    spec
     
  9. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi hall.
    I use these sensors from Amazon, 5 off for £1.79, makes them a disposable item.

    E
     

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  10. spec

    spec Well-Known Member Most Helpful Member

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    Last edited: May 26, 2016
  11. halleffector

    halleffector Member

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  12. spec

    spec Well-Known Member Most Helpful Member

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    Glad that this sensor looks OK.

    Yes, because the sensor works on a capacitive principal it should detect pure water OK.

    spec
     

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