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Topic: stevensons shield (Read 9 times) previous topic - next topic

carl47

I have completed my indoor weather station:

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1265087241

The next step is to include sensors from a remote outdoor location.
All my sensors use an unsigned integer format. I have written the code
to send the sensor data from a remote location:

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1268083394

A common way to house the sensors is in a Stevenson Screen:

http://en.wikipedia.org/wiki/Stevenson_screen

The traditional Stevenson Screen is a box shape, constructed of wood, in a double-louvered design.
This is very costly and needs to be maintained-also costly.
There are many examples of home built screens:

http://www.loganvillageweather.com/station/stevenson.html

I have used a polystyrene produce box as my shield.
The sensors are mounted in a wooden box covered by the poly box.

A Stevenson screen or instrument shelter is an enclosure to shield meteorological instruments against precipitation and direct heat radiation from outside sources, while still allowing air to circulate freely around them.

The poly box shields the sensors but to circulate air I have used a 12v fan. I have battery backed 12v available and this is not a problem.
The cost problem is solved by the poly box being disposable and very cheap




The bottom of the box is 1.3m above the ground.
The support is a galvanized pipe concreted into the ground.
Concrete is a good conductor and this pipe makes a good earth point.

More design information is available from:
Download Stevenson.pdf


http://sourceforge.net/projects/arduinoweather/files/  

westfw

So that's like a styrofoam cooler as the outer layer?  (You said PS, but not "foam"; in the pdf it does look like foam...)

Styrofoam is not particularly UV-resistant.  A coat of paint might help.   And around here, it seems that certain critters will chew on it :-(  This may be made up for by the cheap and easy replacement...

Small to mid-sized styrofoam boxes may be available from your local medical facility, and available free for "industrial reuse."  Apparently such things are used to ship assorted pharmaceuticals (vaccines, etc), and since garbage disposal is charged (essentially) by volume and styrofoam boxes are this awful, the recipients are anxious to get rid of such things...

Ran Talbott

And where I live (at 4400 feet),  the UV chews on plastics  :)

I did a version of this design,  but without cutting the louver for a flip-up front,  because the housing is readily-accessible for (dis)assembly from ground level.  The price of the vent louver has gone up quite a bit since that page was written:  it was closer to $10 than the $3 the author paid.   :(

But I found that notching the edges at the bend points,  and C-clamping it to a piece of 1x6,  sufficed for getting good-looking bends without a proper brake.

It's probably not good enough for a "professional" weather station,  but it seems to have done as good a job as having the temperature sensor well out of the sun under a 10-foot-deep porch.  It eliminated the 15-degree-plus error that appeared when the sun shone directly on the sensor.

Pauly

Nice projects!  I have made a weather station as well, but was running out of housing ideas!  I'll try maiking one of these shields.

Pauly

Has anyone tried this without wires?  
By that I mean using something like a WiShield to connect wirelessly to your home network.  Of course doing this then distance becomes a factor as well.
I wonder if the metal screening would hamper the radio signal?

carl47

westfw

Yes it's foam, pure PS foam with no protective coating.

Here in Aussi we use millions of them. They are used once and
mostly recycled.
The size I'm using is a standard broccoli box.
We can purchase them for a $1 at the supermarket to carry home our vegetables with a little ice.
They degrade in the sun but are usefull for about a year.




Ran Talbott

Thats a good looking site.  I like that shield and it sure does
look like a bird box.
I have noticed birds resting on mine as it has a nice flat surface for them.

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