This sensor combines a Chemetron heat detector and a learn mode wireless transmitter in one unit. A built-in thermostat trips the transmitter when the temperature at the sensor location reaches about 135deg.F.
Since many fires grow rapidly in intensity causing a rapid temperature increase, the thermostat also trips the transmitter if the temperature rises 15deg.F or more, per minute.
All models can be powered by one 9-volt alkaline battery that can last 12 to 18 months, or by one 9-volt lithium battery that can last up to twice as long.