@packbat there isn't usually a CO sensor in the building because there's nothing that would feasibly produce CO; the heating is electric and there's no generators or anything, our coworker brought this ancient one in to see if it was why he was getting bad hay fever (yeah i don't know either) when he was in his office for extended periods
i could believe it being broken, considering the condition of the thing, but there's still that nagging feeling
-F