digging thru some files...leak detection

[RPAspey]

I was digging thru some older files and found this Infra Red pix I took while trying to find the source of water in a lower cubby/storage area. I waited for a cold/rainy day, turned on the heat in the camper, and using a FLIR camera I searched for a temperature differential indicating a colder area - showing up as a brighter area. The leak area is colder due to water retaining its temperature a little longer than the dryer areas...Its not a technical explanation, but that's how I understand it. anyway it's amazing that the water came from a tiny slice about 1/8" long in the roof, and ran down the corner until it hit the cubby. the other not as light areas are ones that are damp. The circle is a LED light on the wall.