Building a radiation shield

[ruskinPalms]

The thermometer in my weather station is messed up so I ordered a new one. I needed a radiation shield for it. I am going to post a few pictures and a little descripion of how I made it.

[ruskinPalms]

Supplies and tools:

Used old pot bottoms, nuts and washers, bolt rod things from home depot, 1" PVC pipe and fittings, white spray paint, a couple machine screws, PVC plastic cement, duct tape to make a washer. Screwdriver, power drill, hack saw, utility knife, and maybe some other simple tools as needed.

[ruskinPalms]

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[ruskinPalms]

Cut squares out of the pot bottoms. Cut a circle big enough for the pipe fitting to fit through on a couple of them, ended up only using one of the bottoms the pipe hole though.

Cut the PVC pipe with hack saw. Made a point on a shorter piece so that it can be driven into the ground. Put male and female finttings on the pipe so the whole thing is modular so that it can be taken down easier for hurricanes and such.

[ruskinPalms]

Put the pot bottoms on the bolt rods with washers and nuts starting from bottom up. Pretty tedious....

[ruskinPalms]

A couple of coats of glossy white spray paint.

[ruskinPalms]

Putting it together. Used a pipe cap and a male pipe joint to hold the shield to the top of the pipe. Used a machine screw to secure the bottom of the shield to the pipe. Used another screw to make a simple hanger for the sensor inside the shield.

[ruskinPalms]

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[ruskinPalms]

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[ruskinPalms]

Screwed the whole thing onto the pipe that I pounded into the ground outside earlier. Here it is next to my old weather station. I hope this shield works. It is passive, no fan. But, I left the bolt rods out the top in case I want to expand on the design in the future ( like a solar powered fan some how). Most likely, I am just going to moint a plate of larger diameter to the top to provide some more shade.

[ruskinPalms]

That's it. It actually seems pretty solid. Took some time to make, but really not all that difficult.

[spockvr6]

(ruskinPalms @ Jan. 08 2008,21:38)

QUOTE

Most likely, I am just going to moint a plate of larger diameter to the top to provide some more shade.

Bill-

Definitely do this.

It will not only shade the sensor more effectively, it will also keep rain out.

I think youve got a great looking shield there!  

I would certainly look into adding a fan.  I noticed drastic improvements in accuracy versus the same shield without a fan.  And, if you do add a fan, make sure it pulls air across the sensor (rather than blowing across it) as the fan will add a small amount of heat to the air which you do not wish to measure.

[freakypalmguy]

Very nice Bill,

I just got my weather station and will be building one now also. Thanks for the tutorial.

Matt

[sonoranfans]

(ruskinPalms @ Jan. 08 2008,21:38)

QUOTE

Screwed the whole thing onto the pipe that I pounded into the ground outside earlier. Here it is next to my old weather station. I hope this shield works. It is passive, no fan. But, I left the bolt rods out the top in case I want to expand on the design in the future ( like a solar powered fan some how). Most likely, I am just going to moint a plate of larger diameter to the top to provide some more shade.

If you need more radiative shielding, a more reflective surface would help.  Foil is a bit more reflective than white PVC, especially in the UV range, and aluminum dissipates any heat buildup faster than PVC, thats for sure.  Since overnight low temps are my main concern, and I have alot of canopy, I dont have much interest in what the sun effect on sensors is, but the best shielding is highly reflective.

[ruskinPalms]

Thanks everyone. I added a top plate to help when the sun gets more overhead and intense. Tom, I may try a reflective top plate of some sort. Thanks for the suggestion.

[MattyB]

Nice work Bill!  That looks really professional.  I like how the center post is offset so the sensor ends up in the center of the radiation shield.  I wouldn't have thought of that until after the fact.