Watermark and Vegetronix Soil moisture sensors
- Thread starter Adomas
- Start date
BeanieBots
Moderator
Welcome to the forum.
There have certainly been many moisture projects done here but I don't recall one for that particular sensor. People usually make their own.
Is it just the probe or is there electonics as well?
More details or a link to the datasheet would help.
There have certainly been many moisture projects done here but I don't recall one for that particular sensor. People usually make their own.
Is it just the probe or is there electonics as well?
More details or a link to the datasheet would help.
Hi all,
Both a probes, which measures resistance similar to gypsum block but improved with stainless steel etc. The manufacturer page: http://www.irrometer.com/sensors.html and for wiring see here: http://www.usu.edu/cpl/PDF/WatermarkOperatingInstructions2.pdf
For Vegetronix probes see here: http://www.vegetronix.com/Products/VG400
I found information that the Irrometer/Watermark sensor could be used with Hobo loggers, which measures output voltage by simply adding known resister and then by equation voltage could be recalculated to kOms. Sensor to these Hobo loggers are connected via stereo cable with three wires.
So I am interested how could be these sensors-probes attached to Picaxe loggers and does anyone tried this before. i have searched the forum but with no success. Thanks. Adomas
Both a probes, which measures resistance similar to gypsum block but improved with stainless steel etc. The manufacturer page: http://www.irrometer.com/sensors.html and for wiring see here: http://www.usu.edu/cpl/PDF/WatermarkOperatingInstructions2.pdf
For Vegetronix probes see here: http://www.vegetronix.com/Products/VG400
I found information that the Irrometer/Watermark sensor could be used with Hobo loggers, which measures output voltage by simply adding known resister and then by equation voltage could be recalculated to kOms. Sensor to these Hobo loggers are connected via stereo cable with three wires.
So I am interested how could be these sensors-probes attached to Picaxe loggers and does anyone tried this before. i have searched the forum but with no success. Thanks. Adomas
I have never heard of either sensor though I have vaguely heard of the Manufacturer.
I've never seen the names mentioned on this Forum. Have you tried a Forum SEARCH ?
Assuming they don't need any special driving, the first one seems to be a resistance output so you could use it in a potential divider.
The Vegetronix says it gives an output of 0 - 1.8v so possibly could be measured directly using PICAXE ADC.
But as I don't know precise details I'm just guessing.
I'm sure many will suggest making your own probe and then debate best materials.
Up you. Time versus cost.
Buy one, get it working and post back under the Projects section.
I've never seen the names mentioned on this Forum. Have you tried a Forum SEARCH ?
Assuming they don't need any special driving, the first one seems to be a resistance output so you could use it in a potential divider.
The Vegetronix says it gives an output of 0 - 1.8v so possibly could be measured directly using PICAXE ADC.
But as I don't know precise details I'm just guessing.
I'm sure many will suggest making your own probe and then debate best materials.
Up you. Time versus cost.
Buy one, get it working and post back under the Projects section.
BeanieBots
Moderator
Page two of the instruction manual gives the answer.
"In order to directly connect a Watermark sensor to a
datalogger, the sensor must be equipped with an in-line blocking capacitor (CSI
model 257 sensor, $90, see below)."
Sounds like it's a basic probe requiring AC drive.
This has been covered before. A search should show up quite a bit.
(or wiat for eclectic to find it for you
)
"In order to directly connect a Watermark sensor to a
datalogger, the sensor must be equipped with an in-line blocking capacitor (CSI
model 257 sensor, $90, see below)."
Sounds like it's a basic probe requiring AC drive.
This has been covered before. A search should show up quite a bit.
(or wiat for eclectic to find it for you
)I know this that the data logger manufacturers claim that both probes need AC excitation. This is because DC can cause polarization of the sensor and electrolysis (micro bubbles). But I found an article by R.G. Allen in which these both DC effects are analysed in detail and he argued that sort readings for 10-40 ms if they are done only once per hour will not polarize the probe. You can see this here: http://www.kimberly.uidaho.edu/water/swm/WM_Hobo2.htm
Actually, I am trying to find some cheaper solutions than buying complete weather station for several hundreds pounds (after shipped in EU from USA the price increases up to 4x). Mostly manufacturers in Europe of soil moisture loggers produce a very high cost and scientific grade equipment which is too expensive for me.
Actually, I am trying to find some cheaper solutions than buying complete weather station for several hundreds pounds (after shipped in EU from USA the price increases up to 4x). Mostly manufacturers in Europe of soil moisture loggers produce a very high cost and scientific grade equipment which is too expensive for me.
BeanieBots
Moderator
Well, ec let us down.
Never mind, put "soil moisture" in the search box and you'll be well on your way.
I'd suggest avoiding DC completely, even very short low value bursts will have an accumulative effect.
Make your own probes too. The hardest part is fixing copper wire to steel.
It's all there in the archives. Too many links to list. Happy reading!
Never mind, put "soil moisture" in the search box and you'll be well on your way.
I'd suggest avoiding DC completely, even very short low value bursts will have an accumulative effect.
Make your own probes too. The hardest part is fixing copper wire to steel.
It's all there in the archives. Too many links to list. Happy reading!
educate-yourself
“When you cut a piece of wire to a specific length known as the "cubit" length, that wire will resonate or act as a transformer to special cosmic energies and draw that energy into the wire.”
http://educate-yourself.org/dc/orgonegenindex.shtml
“When you cut a piece of wire to a specific length known as the "cubit" length, that wire will resonate or act as a transformer to special cosmic energies and draw that energy into the wire.”
http://educate-yourself.org/dc/orgonegenindex.shtml
inglewoodpete
Senior Member
boriz, relevance?
BeanieBots
Moderator
Lovely example of some of the extreme BS that can be found out there.
A good reminder that some people spend a lot of time writing and publishing stuff that they dreamed about the night before. Unfortunatley, some people think if they read it on the internet, it must be true.
As ip says, relevance?
A good reminder that some people spend a lot of time writing and publishing stuff that they dreamed about the night before. Unfortunatley, some people think if they read it on the internet, it must be true.
As ip says, relevance?
Adomas, all this AC-DC stuff has been covered in this Forum years ago, so most people are familiar with the general issues.
Have a search on "moisture" and you may find something helpful (plenty unhelpful naturally).
How much do you want to spend (max)?
What is your electronics experience?
School project?
Have a search on "moisture" and you may find something helpful (plenty unhelpful naturally).
How much do you want to spend (max)?
What is your electronics experience?
School project?
Adomas,
You may be interested in looking at a "roll your own" soil moisture sensor from Make magazine. At least the price is right!
http://www.cheapvegetablegardener.com/2009/03/how-to-make-cheap-soil-moisture-sensor.html
You may be interested in looking at a "roll your own" soil moisture sensor from Make magazine. At least the price is right!
http://www.cheapvegetablegardener.com/2009/03/how-to-make-cheap-soil-moisture-sensor.html