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Moisture Sensor

Is there a resistance scale for the moisture sensor or is it an on/off switch?

is this feature available now on the device?


  • 10 Comments sorted by Votes Date Added
  • Is the moisture sensor RoHS? Am I going to kill my cats by sticking it in their water bowl?
  • The moisture sensor reports that something is either wet or dry. We're just starting to ship them to Kickstarter backers, and should have enough stock to ship to anyone next week.
  • the picture looks like a resistive device - dry has a high ohm reading - wet has a much lower ohm reading my many magnitudes. In the picture I do not see a float switch-like device. I have worked with the Aginova devices which deliver an on/off status, but internally a resistive threshold is crossed when the resistance between to metal probes are immersed in liquid decreases.
  • So does the whole probe have to be sitting in standing water for it to trigger? I want to use mine as a basement water leak sensor but I want it to trigger before I have to replace all the drywall, carpeting, and insulation in the basement at a cost of $10,000. Will it work for that?
  • Only the tips of the sensor need to contact water, the sensor is about 3 or 4 inches long with the moisture contacts being about an inch long, complete submersion may damage the sensor. The sensor is very responsive, I first tested it in a glass of water barely submerging the tips, it immediately sent a moisture notification, 2nd test I wiped a wet cloth across the sensor, again immediate moisture notification. I plan to use this sensor in my laundry room that has no floor drain.
  • Correct, water just needs to bridge the two gold contacts. It's sensitive enough that a sweaty palm will trigger it. It's recommended that you mount it vertically so that the whole thing doesn't get submerged. It shouldn't damage it, but may lead to funny signals.
  • LOL, I suppose you could lick it like a 9v battery to find out.
  • I'm considering encasing it the whole thing (except the contacts, of course) in Sugru -- any thoughts if this'll cause any problems? (See
  • I tested the moisture sensor by shorting the two legs with a wire jumper, and it showed "wet" when shorted. It appears to work as an open/closed switch sensor.

    Also, you can extend the sensor contacts with wires and it still registers properly. So it seems fairly versatile.
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