thermostat for humidity

has anyone ever heard of a thermostat that reads humidity and operates off of humdity levels? I guess that wouldn't be called a thermostat huh. Anyways, just had an idea for controlling humidity using one (if it exists) during shed cycles....

My humidity hangs around 50% or so and I am generally not home during the day to mist

thanks!

yeah that a barometer or some spelling like that i beleive. but even that i believe records pressure. and uses a mercury capsule

you're talking about a Hygrostat or Humidistat, and yes they do exist. Not sure they're really practical for our hobby, though...