Resurrecting this topic.
I got my Atlas, and I am too having issues with UV reporting. While being a little low isn't TOO horrible, what bothers me is that there are times throughout the day where UV will briefly hit ZERO (and then return to bouncing between 1 and 2, when other nearby stations are reporting a solid 3 with an occasional 4.
I live in Phoenix, AZ. It was a completely clear sunny day today. At 11:44am I had a reading of zero briefly (among a few other sporadic zeros throughout the day). No way could there have been a zero UV at that time. Checking back over my daily charts (I've only had the Atlas for about a week), I see some instances from other days where I had a zero reading for UV during the day.
I can understand a bit of a LOW reading, but a ZERO? No way.
So anyway....my reasoning for resurrecting this topic. Since I haven't yet taken apart my Atlas to get a good look at parts, has anyone tried making their own diffuser to replace the stock one? Since I don't yet know exactly what the stock one looks like, I can't yet come up with something that may allow a little more light to pass through...but I am trying to think of something that could be made to replace the stock diffuser.
Anybody done anything like this yet to correct the low UV readings?
I did do a test like nincehelser did, and shined a flashlight on the sensor, and it went right up to 15. So, I know the sensor itself is working. It does just seem to me (as others pointed out) that too much light is being filtered by the diffuser.