UVN800 UV Sensor

[egwillim]

Just set up new UNV800. I'm not sure if the sensor is working. WMR200 recognizes the sensor. Even on a sunny day I still get "0" reading.
Is there any way of testing the sensor? Will it react to strong artificial light or does it react  to sunlight UV only?
I have heard of some problems with the UV sensor so would like to determine if I have a unit malfunction before I return it to Oregon.
Appreciate any suggestions.

[Scalphunter]

Well don't know where you are located. Guess that is an secret. BUT in northern climes the sun may not  be high enoungh to trigger and reading. Not many days here are sunny but I use to tilt the  8000 to get some sort of an reading. Not until about March at this Latitude  did the 8000 start to work in an vertical position. Even my freeby VP2 uv  sensor read any thing at this time of the year. Sun angle just too low for them to trigger an reading.  As to what they read it is UV  not sun light. So an strong light will do nothing. Never did try my  mining black light on them to see if they would read it as it gives off long and short wave  UV.

John

[stevebrtx]

On the other side of the coin I'm seeing 11 on a sunny day (which is most days), even this time of year.

[egwillim]

I guess I may be expecting too much from the UV sensor. Yes, the sun is still low at this time of the year. (44.1N, 79.45W). I checked the local airports and note that they still have low readings.
Guess we can't complain, I haven't had to start the snow blower this year. Located approx 40 KM North of Toronto.
Paul

[Skywatch]

Just out of curiosity has anyone noticed a change in accuracy with age of the sensor? When I first got my UVN800 it too would only read 0 or 1 on sunny days. But it seems with age the sensor has improved in accuracy. At least this same time of year it's recording a 3 where last year it didn't get higher than 2. On an average day without tilting the sensor now I find it to correlate with other comparison stations in the area. As I don't have the UV sensor on my VP2 I can't compair with that but with other Pro2 pluses in the area. But it seems with time the sensor's accuracy improves. At least that's what I observed. I'd watch the sensor for a while. If it gives a 0 it most likley works. Like Scalphunter mentioned, try tilting the sensor. If your's is like mine with time the accuracy shall improve. If nothing than it might be a problem. Also make shure there are no shadowing obstructions near by.

[gadget_guy]

This time of the year I'm lucky to see a max reading of 1.  Not unexpected though.  The sun being lower in the sky and all.  In a few months the readings will start rising rapidly.

[egwillim]

Happy to report that my UV sensor appears to be working. We had a period of sun at mid day. Sensor recorded a 2 for a short while. I'm now set and ready for those long summer days.
Paul

[Skywatch]

That's good to hear. I'm already waiting for the UV to steadily rise. Been cloudy lately so I havn't gotten a good reading but when 3 jumps to 4 I'l know spring is just around the corner.

[obyapka]

My very first UVN800 sensor arrived today and it was detecting 01 right from the off on my WMR200....

The instructions confuse me.

Is this or is this not, an outdoor sensor?

It comes wioth a ground spike, a wall bracket, it even tells you about using the batteries down to -30 (lithium)... but then in the "precautions" section... "Do not immerse the unit in water. If you spill liquid over it, dry it immediately with a soft, lint-free cloth."

I've read numerous tails about these failing after a month, or just out of warranty... so I presume it should be an outdoor sensor... but it's like OS are creating a caveat so you cannot claim for outdoor use if it rains!

[stevebrtx]

Mines on the roof about 2 years now, we get 30" of rain a year, just got 2.5" in the last few days, never had a problem although I did notice when I cleaned the dust from the sensor on top it increased the readings.

[FrozenPenguin]

Mine is sticking out of the snow at the moment, but the sun is so low here still I get no readings from it.  I tilted it about 45 degrees, but still nada.

[stevebrtx]

Boy, I don't know how you folks live like that. We've been cloudy for a week and I, for one, am about to go nuts, I need the sun. Also helps to give us some heat, it was getting darn chilly as the houses cooled off.

[FrozenPenguin]

We barely see the sun from november to march.  Daylight from 9:30 to 15:00 at the worst.  If you go north in Norway, you're in the dark all winter.  It's tough for sure, and I'd seriously hate it..however it's convenient for me as I have an eye disease that makes me extremely light sensitive. 

[egwillim]

UV reading at 2, noon hour on sunny days at 44N.
I am now recording UV readings between 10AM and 3PM on sunny days.
Snow today so I don't expect any UV readings.

[stevebrtx]

We're at 20N and have sun for the first time in a week, so we're at 11 and I just got into shorts for the afternoon.

[sjg1976]

I've found by angling mine slightly I'm able to get better readings.

Have no had readings upto about 4 in the uk.
So not too bad.

Doesn't seem too work very well if it's not angled up, buy guess the sun is quiet high enough here yet.

[egwillim]

I now have readings that vary between 1 and 8,  09:00 to 16:00 on sunny days.

[Skywatch]

It's first week of April and we're already hitting 9 on the UVI and the sensor is looking straight up. I confirmed that the sensor receptor at first purchase date has innaccuracies. But with comparing with other stations in the area giving UV seems accurate after a year and a half.

[ArmySlowRdr]

1st year I had the UV sensor it seemed to read pretty low for a while, then one day it just started "working" with readings often in the 8 to 12 range.

I took the station off line for a while and put it back on line 2 days ago. Changed the batteries in the UV sensor and did a reset. It is being recognized. BUT for example right now the reading is 0 and the highest it got the last 2 days is 2 which of course is not right.  Wonder what causes these things to be flakey...  I could just go out and buy a Davis Pro 2 with FARS and uv/solar sensors right now.....  but just reading through threads it seems all the stations are flakey. OS does seem to be accurate WHEN the sensors are being picked up and working. I am just thinking the close to 1500-2000 to get the Davis compared to the 300 or whatever for the OS--I am not sure the Davis is REALLY 500-600% better.....

[ArmySlowRdr]

I stand corrected in my post above more like 1250 for the Davis along with WD and WD live--didn't realize Ambient had "sales" prices that one obtains via a link sent by email.

I think I will try another OS UV sensor and I want to move my anemometer up to the roof--already have the hardware and extra solar sensor to do that so..

..I'll wait on the Davis one to two more "disappointments".