Nearly all mechanisms that fight the danger of fire operate with the help of some sort of embedded sensors. No one can speak with any clarity about the life and the working of these sensors. According to some learned experts these sensors need to be replaced over a specific period of time. Some of the sensors who are deputed 10 to 15 years are not available in the market now. There is a possibility that you might change the entire fire protection mechanism due to the unavailability of sensors.