Don't know what a standard sensor is. I asked about humidity and that part number was suggested. Was told it should be about 20 bucks. I paid a little more. What's your suggestion? I'm just bluntering through the dark, here.
I'll give you a laugh. For the next part, a fluid level indicator made with the pot from a game controller, a ping pong ball, and a piece of piano wire.
GadgetBandit