On Saturday, March 7, 2020 at 8:22:52 PM UTC-8, WaltWX wrote:
Here's another reference to inexpensive, light and disposable sensors designed to detect when radiosonde balloon packages ascend in clouds. They accurately detect the cloud boundaries:

Measuring cloud properties from meteorological radiosondes

https://ams.confex.com/ams/14CLOUD14...per250270.html

Walt Rogers WX


I found the instrument that may work. Low cost is relative but free shipping.

https://www.amazon.com/Solar-Light-P.../dp/B077Y88DPB

only $700 free it will fit on the instrument panel cover 1.8"X1.6".

Richard