Stephenson screen

[neil]

I have built a small screen made from 4 gas vents measuring 229mm x 229mm and a few bits of pvc cladding i had laying around
There is a gap between the lid & the louvres to allow heat to escape from the top
I intend to experiment myself but thought i would ask for other peoples advice and experiences
I know its not a proper screen because its not large enough but felt it must be better than the supplied screen.
Now for the question at the moment i have left the solar screen covering the transmitter would it work better with the supplied screen on or off ?
any views or experiences are most welcome

Neil

[Charlie]

Most of us have found best performance about 5-7 feet off the ground, and in the shade. To be strictly by the book, the location and screen have relatively stringent requirements, however the acuracy of the unit would likely mask the difference.

Not so between sun and shade, however - you'll be alarmingly too high when the sun shines directly on the unit.

[neil]

Thanks for the reply charlie
having tried the screen with and without the supplied solar screen the following results where found compared to the the met office site at manston (about 4 miles away). http://www.metoffice.gov.uk/public/weat ... ast24hours
With the solar screen and my home made screen approx 6 degrees higher
just my home made screen about 4 degrees higher
my suspicion is that with both screens in use the airflow to the sensor was reduced
so after just over 3 years i have taken the plunge and moved the whole thing to a location where the temp sensor can be almost permanently shaded the only exception is first thing in the morning when the sun is not so strong.
a slight compromise due to the wind speed being slightly more compromised by structures.
but the over night results are very nearly perfect again compared with manston.
I have not fitted my screen yet but at 04.00 both station were at 14 degrees and at 0900 both were at 20 degrees.
I suppose it proves you must be prepared to compromise but also seriously consider you initial location when you first set up your station
Neil