1-Wire UV Sensor

Anyone know if someone has 1-Wire UV Sensor’s for sale?

Thanks.

Dwain

Hobby-Boards has a 1-Wire solar sensor…
http://www.hobby-boards.com/1wireboards/sr2-r1_solar_radiation.html

However I haven’t come across any UV sensors in my searching and I am still trying to figure out which would be more beneficial to a Weather Station set up myself…

-Bob

all that would be needed is to get a solar sensor that is tuned to just the UV wavelength instead of the normal light wavelength
i know Jim Jennings did come across one that could do it, but thats like 5 years ago now

Or a filter that blocked all wavelengths but UV. Like a pair of sun-glasses in reverse :slight_smile:

[quote author=41South link=topic=8258.msg58414#msg58414 date=1111374584]
Or a filter that blocked all wavelengths but UV. Like a pair of sun-glasses in reverse

Or use some lateral thinking…install two sensors, cover one with a lens from some sunglasses, then do a difference in levels between the two to extract the UV level. Perhaps a little complicated, but it’s a solution if all else fails :wink:

That would work if the sunglass only blocked UV, but unfortunately it’s likely to have a major impact on the visible too. Safety glasses maybe, I think I have seen those claimed to block UV.

I got a quote for these http://www.sglux.de/home/tw30sx.pdf, $30/pce for <10 as I recall.

I found the following at digi-key.com:

PDU-V114-ND - PHOTODIODE UV 17.63MM SQ TO-5
Response: 190 - 1100nm
Price: 28.00 in single qty

PDU-V104-ND - PHOTODIODE UV 2.98MM SQ TO-46
Response: 190 - 1100nm
Price: 19.99 in single qty

I say the surface area increase in the first one is well worth the $8.00 difference in price. It should be an easy swap for the hobby-boards solar sensor… not sure about the ibuttonlink.com modules, though. They state thier’s is a “photocell” which I would interpret as a resistive sensor not a photo-diode. But, heh - what do I know?

Dwain

Dwain,

Those digi-key parts cover the visible spectrum (actually into infra red even) with some response in the UV, so you would need a UV only filter (for which I don’t know any low cost source) to get any useful measurement. If you look at the datasheet of the part I referenced above you’ll see it only responds to UV, it needs no filter.

[quote author=nikoshepherd link=topic=8258.msg58475#msg58475 date=1111421026]
That would work if the sunglass only blocked UV, but unfortunately it’s likely to have a major impact on the visible too. Safety glasses maybe, I think I have seen those claimed to block UV.

Hmmm - thinking about this it seems all back to front. Isn’t UV the only wavelength we want to let through to the sensor - not block it out. #-o Looks like the Digi-key sensors might be worth a play with.

Not with the design I suggested. This is how it would work (if you can find something that blocks only UV and allows all other visible light through).

  1. Create two identical sensors.
  2. Put them in full sunlight when you expect the max levels of UV and measure the output from them. Say you get 100 mV from each sensor
  3. Now cover one sensor with something that only blocks UV. The output from that sensor will drop, say to 80 mV.
  4. Do some maths…Visible Light + UV = 100. Visible Light = 80. Therefore UV = 20.
  5. Now try them on a cloudy day when the UV is being blocked by the cloud. What you shoudl find is that the two sensors give much closer readings. So you might get something like Visible Light + UV = 50 and Visible Light = 48

The amount of UV is therefore proportional to the difference in readings between the sensors. Big difference means a lot of UV, smaller difference means less UV.

Was that for any number <10?

Yes, I may be able to do better, I’m thinking of getting a couple, anyone else in? I’ll absorb the shipping to me, so just be device plus mailing cost to anyone who wants one.

Yep, that should work. Ill try it at the weekend, I have some Uvex safety glasses that have a nice sharp cutoff at 400 nm so pray for some burning sun :smiley:


That’s an amazingly sharp cutoff!

I might go in on that… Let me know if you decide to order so I can say yes/no.

Be interesting to see what happens, unfortunately when I look at the data sheet the silicon detectors I have, and even those UV enhanced ones like dcoufal referenced have very little response < 400 nm and the UV’s are at:

UVA 400 nm - 320 nm
UVB 320 nm - 290 nm
UVC 290 nm - 100 nm

The response of the dcoufal one:


I guess the other question is can Brian provide the support in WD to do the comparison calculations? 8) It would mean having 2 1-wire (or other) solar sensors and then telling WD which is the “UV” sensor. Sounds like a cool idea, I hope it works as planned. :slight_smile:

A whole other issue is calibration, with solar you can point the thing at a clear sky sun and call it 1,000, but I wouldn’t know where to start with UV…