The methalyzer can detect methanol vapour and sound audio alarms and trigger external relays to shut down machinery etc.
It is available as a 'bare bones' pcb or packaged with some or all of the components, depending on which option is required.
The programming code is for an arduino uno and, with the parts list, is available as 'open source'. CLICKY LINKY
Not suitable for sensing end of de-mething stage.