I want to build a Chlorine gas alarm for our pool/hot tub mechanical room, we use automatic chlorine feeders that use chlorine pucks, and can be quite dangerous if someone doesn't close them properly or if they store the pucks improperly and they get wet (lots of nasty off-gassing, burns the eyes, throat, and possibly much more).
I want to make it basically like a regular smoke or CO alarm, if anyone knows if there is a sensor available or another work around, that would be great, thanks!
Have you thought of the liability for your project. If you check none of the DIY parts are approved for life support or in the environment you are talking about. It is much more cost effective to purchase it they pay for injuries if it fails.