Ways Of Shielding The Sun?

[SP1986]

Finally got a computer link weather station, my temperature sensor has the good old roundhouse stevenson screen but it's not enough really - anyone got any suggestions to what I could use to stop the suns rays affecting the readings.. the sensor is about 2.5-3m off the ground and is mounted on a poll on the front of a self built greenhouse frame.

[Terminal Moraine]

I've used a plastic 'mini-screen' for years with the sensor mounted on a pole on the house roof and have never encountered any problems, in as much as it always agrees well with the 'official' thermometers mounted in a Stevenson screen at 1.2m above ground level, and allowing for the fact that the sensor is 10m above ground level.

What makes you think your sensor is not behaving properly Stephen? Are you perhaps getting secondary radiation from some source nearby?.

[SP1986]

It's possible, there is a roof about a metre from the sensor, but Ive stuck a small stevenson screen box made from white material (plastic based) over the sensor and for now it appears to be working. The readong was showing 18.1C (theres no way thats the case), it's going down slowly but surely now.

[Terminal Moraine]

A roof a metre away would certainly be close enough to have an effect on the temperature if it was sunny and the wind was light or if it was calm.

Is your mini Stevenson screen something you've made or something bought? I got mine from Davis for about £25 and must admit I was sceptical when I first saw it, however its' worked admirably.

I was further re-assured when I saw top end automatic stations costing upwards of £3000 using very similar mini screens for their sensors.

[Osbourne One-Nil]

I've seen lots made from upside down trays that you normall put under flower pots, painted white.

Here's a good link - http://www.wxqa.com/shields.html

And I see Dimitris (Weather1967) has a link on there!

I bet he's 42.

[Thundery wintry showers]

I remember when I first had a homemade Stevenson Screen installed it was single-louvred and this turned out to be insufficient to prevent artificial warming from the sun's rays, even in November (this was back in November 2006). Installing a second set of louvres solved the problem.

Could your problem be similar?

[SP1986]

Do you think it's possible say making a plant dish stevenson screen will cure the problem (put over my current one?)

Obviously the way it's set up a box stevenson screen could be done but it would be quite awkward.

[weather1967]

Do you think it's possible say making a plant dish stevenson screen will cure the problem (put over my current one?)

Obviously the way it's set up a box stevenson screen could be done but it would be quite awkward.

Hi all

Stephen you can make a Stevenson screen box with wood but if you make it without double louvers you can make a patent with a fan like me ,it have correct temps like Davis where i had test it .

http://users.otenet.gr/~meteo/project_stevenson-screen-box.html

A simply solution and more-more cheap it is the plastic dishes ,i do not beleive it after my test the plastic dishes it had better results like Stevenson screen with wood.

http://users.otenet.gr/~meteo/project_radiation-shield.html

Your choice is yours