Hey guys, just received my extra sensor for the WMR200 and put it in a jar and into the sun.
Can I use the same settings as for the WMR928 (1.1 and 7.1)?
I’m waiting for a real clear day to fine tune it, but could anyone (owner of WMR200) give me his settings for this?
Thanks a lot!
The model of weather station shouldn’t make any difference. The model of sensor will, but every jar is different anyway, so 1.1 and 7.1 are as good a starting point as any…
N.B. As the year goes around you’ll find that for best results you’ll need to tweak at least the 100% figure now and again (i.e. a 100% clear noon in June will give a bigger temp difference than a 100% clear noon in December).
I want to set up one of these; what kind of jar should I use?
In case your interested, I just converted a THGR810 to measure light for solar readings. I don’t have a sensor in a jar so I can’t compare…
(Sorry for my English, it is about a translator)
After several weeks of tests, for my case that does not function.
Serge
But for many other people it works very well.
Sorry we couldn’t help in your case. The solution is probably quite simple, but the language problem has so far defeated us. 
@Norcal Dan, yes I’m interested.
I saw some comments about it, so I’m curious how you converted a THGR810 !
Describes how to modify the sensor.
Parts I used:
cds cells – I used 3 of these in series
Potentiometer/Trimmer – used 1 of these to tune the circuit. I wired it in series with the cds cells. I haven’t checked to see what resistance it is set to, but I would guess between 2.5k and 5k. The main thing is you need to get the temp readings in range during full sunlight exposure. The sensor is rated at -30C to +70C. Mine reads about 158F in full sunlight.
The 1st picture shows how me getting ready to solder the cds cells. The humidity sensor is still attached, I just moved it so I could solder. When I was done I put it back in it’s original mounting spot.
The 2nd picture shows the completed unit.
That looks good Dan.
I’m not a technician, so I have to ask around for someone to make it for me.
Do you put the sensor upside down, in full sun?
Yep, in the window sill. I am working on revision 2 of the design where I will have the cds sensors mounted remotely. The THGR810 is not weather proof, so I want to make it easier to mount in an enclosure and keep it dry, and then remote the solar sensors.
Maybe you can put it in a jar :-k 
Is the jar only for water-proofing purposes? If that’s the case do you think a piece of clear acrylic shielding the unit form direct rain would work?
So far I am very pleased with the results of my project. I have ordered more cds sensors and once they arrive I will start on version 2 to see if I can make a remote setup to help with mounting in a weatherproof setting. I currently have the sensor in the windshield of the RV that is pointed roughly south. It does not get any direct sunlight due to overhead tree’s.
Nice looking curve you have there Dan
Thanks. I adjusted to variable resistor from 2k to 4k and brought the max readings into a more acceptable range. Reads about 110F in almost direct sunlight versus the almost 160F I was getting before I made the adjustment. One thing I have noticed is the sensitivity, the thresholds are tricky to get set correctly. Currently using, from top to bottom, 85,80,75,70,65. Not much room between each cloud condition. I haven’t had a totally cloudless day for testing, but I have had total overcast and I know I need 65 or lower to trigger the overcast reading. Today is what I would term partly cloudy or scattered clouds, but as I expected the sensor is reading high due to reflection. So while it isn’t perfect, I am overall happy with how it turned out. I like it better than using a metar from miles away 
