I would use only that one picture, think terminator, of the inferred?, or one like it. Bigger, that would clearly show, what going on. With a caption "if it dark blue, it's wet". And show picture is your instruments in glorified pictures. And your the expert.
I would angle the usp a bit different also, cause that headline indicates maybe you struggle to find moisture. I would imply you have the tool, knowledge s to find the moisture where ever it may hide.