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Radiation shield

Discussion specific to Fine Offset and similar rebadged weather stations
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Mortello1
Posts: 22
Joined: Mon 03 Mar 2014 2:13 am
Weather Station: Maplin N96GY
Operating System: Windows 7 (64 bit)
Location: Ireland

Radiation shield

Post by Mortello1 »

I know you're not meant to expose the temperature sensor to sunlight but is it not designed in such a way as to overcome this, a la below?

Image

I've been getting some erratic temps for the last 2 days, we're having a lovely settled spell in Ireland but I don't think it's quite up to 18°, more like 14/15. Also the rise seems to be too steep, and mostly in late afternoon strangely enough. I'm concerned an aluminium shield might interfere with the signal as I don't really have much choice in where I locate the station.

Thanks. (it's the WH1081 by the way).
water01
Posts: 3670
Joined: Sat 13 Aug 2011 9:33 am
Weather Station: Ecowitt HP2551
Operating System: Windows 10/11 64bit Synology NAS
Location: Burnham-on-Sea
Contact:

Re: Radiation shield

Post by water01 »

You have put the radiation shield on incorrectly. Look in the shield and you will see the slots cut to accommodate the wireless sender, you have used to wrong ones.
David
Image
Mortello1
Posts: 22
Joined: Mon 03 Mar 2014 2:13 am
Weather Station: Maplin N96GY
Operating System: Windows 7 (64 bit)
Location: Ireland

Re: Radiation shield

Post by Mortello1 »

Sorry for the misunderstanding, that's just a picture I took from the website...
AllyCat
Posts: 1132
Joined: Sat 26 Feb 2011 1:58 pm
Weather Station: Fine Offset 1080/1 & 3080
Operating System: Windows XP SP3
Location: SE London

Re: Radiation shield

Post by AllyCat »

Hi,

No, the supplied "Solar Shield" is not adequate for use in direct sunlight. I've measured (intentionally) a 5 degrees C rise in direct sunlight.

There are many threads with suggestions on the forum (particularly in the "Fine Offset" and "Homebuilt" sections), but any metal cover will probably "kill" the wireless link.

A better solution is to locate the sensor out of direct sunlight, but painting the shield "brilliant white" may help. Others have constructed a "Stevenson Screen" and/or added a (solar powered) fan.

Cheers, Alan.
Mortello1
Posts: 22
Joined: Mon 03 Mar 2014 2:13 am
Weather Station: Maplin N96GY
Operating System: Windows 7 (64 bit)
Location: Ireland

Re: Radiation shield

Post by Mortello1 »

Thanks Alan, it's just that most of the places out of direct sunlight are also shielded from the base station ;) Anyway I'll check out those other suggestions, thanks.
hills
Posts: 692
Joined: Sat 26 Dec 2009 8:52 am
Weather Station: Fine Offset WH1091
Operating System: Raspbian Buster
Location: Crafers, South Australia
Contact:

Re: Radiation shield

Post by hills »

Here's what you can do with a set of plastic picnic plates! ;)

This now varies by about 1 degree in the sunniest part of the day when compared to a thermometer I have mounted under a tree over grass, so I'm happy with that.


Image
tumutbound
Posts: 154
Joined: Thu 11 Mar 2010 11:03 am
Weather Station: WH1081
Operating System: Linux, Raspberry Pi (Wheezy)
Location: Port Huon, Tasmania , Australia
Contact:

Re: Radiation shield

Post by tumutbound »

I've bought some solar powered fans (sitting on my desk whirling away at the moment) but still trying to decide on the picnic plate stack or drain pipe method of radiation shielding.
I've been looking for 90 mm pipe with (at least) a 100mm cap for it. So far no luck at the local hardware store.

In the morning, my temperatures can be 5 degrees or more above Tony's South Franklin site which only a few kms up the road.
My weather
CumulusMX (3036)
Raspberry Pi: Wheezy
FineOffset WH1081
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