Topic: Lacrosse-2308 and Radiation Shield Problem

[hollisav]

This is a email that i sent to ambient weather about my problem:
Back in October my son ordered me a Lacrosse-2308AL weather station for my birthday.
The order No. was yhst-37697109791737-161827 which was placed on 10/02/2007.
I received the weather station and set it up shortly after receiving it.
I set it up wired from the outside sensor to the station inside my house.
I soon noticed that when the sun hit the outside sensor the temperature went up to high. 
I had no problems with the outside sensor communicating with the inside console.
The rain collector was working as it should.
I went to your site and ordered the SRS100LX and the WS-2308 Weather station rain gauge mounting shelf.
The order # was yhst-37696109791737-164843.
I received the order and installed everything as instructed and now every time that it rains the outside temp and humidity sensor cuts out and does not send any information to the inside station.  I have to wait for the outside unit to dry out. 
I also noticed that when the sun hits the temperature and humidity solar radiation shield that the temperature still goes up about 10 degrees from the normal temp.
Your ad says that this shield is designed to take care of both of these problems, sun and rain shield.
Did I waist my money?
I had no problem with the rain shield that came with the station accept for the temp problem.
Please let me know how I can take care of this problem.

This is the response I got:
We have not had any issues with the shield, I am not sure if you ae getting radient heat from another source. If you are unhappy with the shield, you are more then welcome to return it but our testing has shown that it works very well. Make sure the sensor is as low as possible in the shield.

About the answer I thought I would get.
Has anyone run into this problem when it is raining out?  Could the moisture be getting into the sensor where the phone wires plug in?  Should I try waterproof putty over the connections?  Any ideas?

I guess I can live with the temp. problem but I would like to get my readings when it is raining.

Thanks in advance
hollisav

[NGRRFan]

Well I haven't had any problems like you have, but here's my suggestion.

First off don't use putty to seal the connections. I'd use a silicon caulk.

Secondly, I drilled a series of 1/8 inch dia. holes in the to of the sensor housing and a couple on each side near the top of the housing to let the trapped hot air escape and give better air flow.

Since my main sensor had to be mounted on the south side of the house I put it in the shade of the eave, which worked fine during the summer, but now since the sun is lower it hits it for a couple of hours or so and things got a bit weird. I installed a baffle/shade that is fully open on the top and bottom to keep the sun from directly hitting the sensor housing. Now my temps are more in line with surrounding stations, within a couple of degrees, so I think my situation has been solved.

[Dal]

Secondly, I drilled a series of 1/8 inch dia. holes in the to of the sensor housing and a couple on each side near the top of the housing to let the trapped hot air escape and give better air flow.

I'm particularly interested in this as I have the same problem. A couple of days ago, my WS2308 was giving a temp reading of +30C! While it was hot here, it wasn't *that* hot.
May I ask how well your solution of drilling holes into the cover worked?

Since my main sensor had to be mounted on the south side of the house I put it in the shade of the eave, which worked fine during the summer, but now since the sun is lower it hits it for a couple of hours or so and things got a bit weird. I installed a baffle/shade that is fully open on the top and bottom to keep the sun from directly hitting the sensor housing.

And can I also ask how you made this? (non-technical person here)

[carterlake]

Are you folks properly shielding your temp/humidity sensor?

You can safely throw away the one which comes with the WS-23xx. It's completely inadequate.

You need to either construct a housing (Stevenson shield) or protect it with the house (up under an eave).

Also, particularly when attached to the house, the sensor should be fan aspirated... I accomplished this with my WS-2300 with a 12v computer fan wired up to a 120v to 12v converter.

I can say that I never had an issue with spiking temp data... wind, that was another story.

[Dal]

Are you folks properly shielding your temp/humidity sensor?{/quote]

I strongly suspect the shielding on mine is somewhat pathetic I'm brand new at this and, courtesy of my lovely wife, only acquired the WS2308 a few days ago.

You can safely throw away the one which comes with the WS-23xx. It's completely inadequate.

Is there a better substitute for the 2308?

Also, particularly when attached to the house, the sensor should be fan aspirated... I accomplished this with my WS-2300 with a 12v computer fan wired up to a 120v to 12v converter.

Or, in my case, a 240v to 12v converter

[NGRRFan]

Secondly, I drilled a series of 1/8 inch dia. holes in the to of the sensor housing and a couple on each side near the top of the housing to let the trapped hot air escape and give better air flow.

I'm particularly interested in this as I have the same problem.  May I ask how well your solution of drilling holes into the cover worked?

Actually this worked pretty well by itself during the summer. I drilled six holes in the top and then two on each of the narrow sides and 3 on each of the wide sides, about 1/4 inch from the top. All these holes let any trapped air escape, so the whole sensor read a bit more normal.

I installed a baffle/shade that is fully open on the top and bottom to keep the sun from directly hitting the sensor housing.

And can I also ask how you made this?

This shield is just a thin piece of white aluminum house siding that goes over the shield in a U shape. It is large enough that it is about 1 1/2 inches away from the sensor housing, so if the existing sensor housing is 2 inches from the wall this adds an additional 1 1/2 inches, and it is about 3 inches taller (top to bottom) than the sensor, so if the sensor is 4 inches tall this is 7 inches tall. It is open at the top and bottom, it is just a flat piece of metal bent into a U shape with flanges on each side.  Finally I added another baffle about an inch from the lower opening of the shield to block and divert any heat radiation from the wall below the sensor.  All this siding I got from a siding company, I just asked them for some scrap pieces so the cost was ZERO!   

It looks a bit kludgy, but it works!

[carterlake]

Is there a better substitute for the 2308?

Like I said, you either need to construct a Stevenson shield and put the sensor out in the open (preferrably 5' off the ground in a grassy area), or you need to shelter it somehow using a structure (house) and then worry about the effects of both temps from that structure and air pockets forming around the sensor.

I provide some resources in that direction on my site...

http://www.carterlake.org/stationsetup.php

This one in particular: http://www.wxqa.com/shields.html

[Dal]

Like I said, you either need to construct a Stevenson shield and put the sensor out in the open (preferrably 5' off the ground in a grassy area), or you need to shelter it somehow using a structure (house) and then worry about the effects of both temps from that structure and air pockets forming around the sensor.

I provide some resources in that direction on my site...

http://www.carterlake.org/stationsetup.php

This one in particular: http://www.wxqa.com/shields.html

I came across your site yesterday and was most impressed. The various ways of constructing shields mentioned there have already given me some ideas which I hope to put into effect once it stops raining here.

[Bob65]

Got my six salad bowl shield installed today and observed a 6 degree drop in the afternoon spike for the 4 hours that the sun is on the sensor. Will watch my QC charts with CWOP for a few days and see if I need a fan or may have to relocate the sensor.

[BPK FL USA]

Sorry to hear I'm not the only one, must be the 'pat' answer from ambient about their shield! 

Here's how we solved it. 
1. I put in a solar fan, purchased from SundanceSolar.com for about $12.00, You'll need to drill a little hole for the fan shaft to thread into the 2nd platethat brought temp down a little still way high) 
2. Then we put the factory sheild back on the sensor and managed to fit it back in the radiation shield, very snug.  The humidity came back up to close to the actual and temp down a little more. 
3.  Finally, as a last resort, I went to the auto parts store and purchased a can of "Chrome" spray paint and very carefully sprayed the outside and top of fins on the radiation shield.  It worked!  The temps and humidity are precise.  The chrome gave it a 'mirror' finish and it reflects the sun much better than white did.)

I would recommend you try just the chrome spray paint first (also easiest and cheapest) as birds in my backyard destroyed the wire from the solar collector to the fan and my temps and humidity are still exact.  We're down in the Florida Keys and the sun beats on my sensor all day!

[wuhu_software]

Sorry to hear I'm not the only one, must be the 'pat' answer from ambient about their shield! 

Here's how we solved it. 
1. I put in a solar fan, purchased from SundanceSolar.com for about $12.00, You'll need to drill a little hole for the fan shaft to thread into the 2nd platethat brought temp down a little still way high) 
2. Then we put the factory sheild back on the sensor and managed to fit it back in the radiation shield, very snug.  The humidity came back up to close to the actual and temp down a little more. 
3.  Finally, as a last resort, I went to the auto parts store and purchased a can of "Chrome" spray paint and very carefully sprayed the outside and top of fins on the radiation shield.  It worked!  The temps and humidity are precise.  The chrome gave it a 'mirror' finish and it reflects the sun much better than white did.)

I would recommend you try just the chrome spray paint first (also easiest and cheapest) as birds in my backyard destroyed the wire from the solar collector to the fan and my temps and humidity are still exact.  We're down in the Florida Keys and the sun beats on my sensor all day!

I was wondering which product you bought at Sundance solar?

Thanks.

[BPK FL USA]

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Hobby Kit with Fan