A random mixture I guess.
I've got a handheld spot thermometer that takes batteries and has a laser to indicate where it's pointing. I've got a thermal imaging camera that's like the handheld doodad on steroids. Then I've got a couple of things that use bimetallic strips, and the house thermostat has a bimetallic strip with a mercury capsule attached, so that when it tips it makes or breaks a simple circuit to the furnace. I also have a rather nice barometer/thermometer that uses a spring for pressure and alcohol for temperature. For good measure I've got a really weird thing attached to one of my heating pipes that looks like a mercury thermometer with the mercury positioned so the bulb is in the flow of hot water through the heating loop. I'd love to know how old that thing is.
I did have a hygrometer that used what looks like horsehair to measure humidity but the hairs broke so now it reads 100% regardless of what's really going on.