Moisture/Humidity Detector question

[SS]

Hi,

I need to switch on sprinkler system based on moisture, can some one please
tell which is a good sensor and where to get them from - also they should
not be very expensive.

Thx

SS

 

[Mark Jones]

SS wrote:

Hi,

I need to switch on sprinkler system based on moisture, can
some one please tell which is a good sensor and where to get
them from - also they should not be very expensive.

Thx

SS

If you're watering something like a lawn, then you'd want a sensor that
measures the soil moisture. Measuring air humidity vs. soil moisture is two
totally different things. Most soil-moisture monitoring devices employ a
simple process of passing a tiny electrical current through two electrodes
stuck into the ground. When the soil is wet, electricty can flow through the
soil much easier than when it is dry. If a sensitive meter is connected to
these probes, then it will "read out" the conductivity, and hence the level
of moisture content.... sounds like a rewarding project.

Also keep in mind, it's best to water at night, when there is less wind,
more humidity, and no sun to burn off all that precious water. Of course
then you must implement a way to avoid over-watering... I've actually seen
mold growing on grass because of that. But anyways, do a google search
(http://www.google.com) for "conductivity tester schematic" or "soil monitor
schematic," etcetera and you'll soon find mounds of similar projects.

Regards,
Mark

 

[Tim Williams]

"Mark Jones" <127.0.0.1> wrote in message
news:SfWdnXRBj6e-rPSiU-KYgg@buckeye-express.com...

Of course
then you must implement a way to avoid over-watering... I've actually
seen mold growing on grass because of that.

On the shadowed (north) side of our house, you can take a walk through
it and churn up a bunch of fine white dust. Yup, mildew...

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
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