Dear PeggyD and WeatherCat station caregivers,
I had checked nearby stations & none report such wild numbers for dew point/relative humidity.
It does sound like a bad sensor, but checking nearby stations is a prudent check.
My husband did clean the outside of the radiation shield but did not dismantle it. As I said, it did give reasonable readings for one day but has since gone back to the very wrong readings. He will try dismantling it & I will let you know.
I don't know how hard it is to dismantle a Vantage Vue, but the radiation shield on the Vantage Pro-2 stations isn't too difficult to take apart. You might check YouTube to see if someone has some instructions. Again, it doesn't seem too likely that would be the problem, but the sensor is a significant investment.
Could you give some suggestions of where I can get a new part if I do need to replace the temperature/humidity sensor?
There are at least 2 vendors who sell parts in the USA at a discount. I've personally dealt with Scaled Instruments for many years:
https://www.scaledinstruments.com/Another vendor that WeatherCatters have used with satisfaction is Rain Man Weather:
https://www.rainmanweather.com/I have a number of other vendors bookmarked, but I don't know if they also carry parts. Let me know if you would like additional suggestions.
Cheers, Edouard