Cumulus Support

The manual on these says that the UV sensor should only be cleaned using ethyl alcohol & not denatured alcohol, which I assume is methylated spirits. If you check the Davis website in the USA there is a section on station maintenance & it says that denatured can be used for cleaning the UV sensor. With this contradiction in mind I contacted Davis Technical Support & their reply was that denatured alcohol can be used as ethyl alcohol is very hard to get.
The Solar sensor should be cleaned with a damp soft clean cloth.
Hopefully this will be of help.

Touchtone wrote:ethyl alcohol is very hard to get.

Everclear 190 proof is 95% ethyl alcohol, which is just about as high a percentage as is stable in contact with air (above that it picks up water on its own). I think in most parts of the US it is pretty readily available in liquor stores.

I bought a bottle and used it to clean my UV sensor, and have seen it suggested informally on one or more weather sites by folks discussing the Davis recommendation. If someone reading this knows this to be a bad idea, please speak up.

By the way, when my UV sensor was about five months old, I did this clean, taking good care to do it during a nearly level part of the light curve on a cloudless day, and concluded that my UV output rose by something like 0.5. I suppose I was mostly removing New Mexico accumulated dust--though perhaps something else accumulates. It has been the better part of a year since, so I should pick a cloudless day soon and try it again.

I was unable to resolve a change associated with cleaning the Solar sensor, as best I recall.