This design adjusts the sensitivity according to pre-set conditions. Some spaces may routinely require an increase or decrease in detector sensitivity. For instance, a highly protected space may require a higher level of protection during off-hours, or a night club may require a decrease in detector sensitivity during normal business hours to compensate for occupant smoking. This allows optimum sensitivities to be used for all conditions. Profile Comparison Fires tend to have unique smoke and heat profiles based upon specific fuels burning.
Plastic fires tend to produce more smoke than flammable liquid fires.
Fire alarm manufacturers have developed databases with details characterizing products of combustion for a large range of fires. These databases include measurements of time dependant properties such as photoelectric detector readings, ionization detector readings, and temperature readings. Data has been grouped according to fuel packages. Specific traits were determined for each type of fuel package. Although each manufacturer uses different methods, analog measurements from individual detectors are compared using algorithms with pre-determined values obtained in fire tests.