On Jan 4, 2009, at 12:00 AM, Dennis wrote: > Looking for a simple alsrm system. something I can strap to one of > the hot pipes on the gen set, set at 120 f and when the temp hits > that, the 12volt bell rings. > > Pretty simple but the only sensor I can find is over 80,00 so far. Go down to Radio Shack and get a normally open snap switch rated for 120 F. It is a very common temperature rating. These are commonly used as high temperature alarms in burglar alarm systems. I have one in my attic. If you can't find it at Radio Shack, any large electronics parts store, catalog, or burglar alarm supplier can get you one. Glue the snap switch with hi temp RTV silicone to the pipe. Wire the switch in series with a suitable alarm buzzer and attach to your 12v. system. If the switch heats up over 120 F the alarm will sound. You might also want to wire a normal on/off switch in series with the alarm to shut it off. Total cost should be less than $10. Larry Z