SAIFRA1 Use on products having single ionization chamber. This algorithm distinguishes between UL burger broil and smoldering polyurethane. Distinction between smoke box and slow moving fire such as broiling and smoldering is also made. This product is resistant to many types of nuisance alarms. SAIFRA2 Use on products having single photo chamber. Distinguishes between smoke box and slow moving fire such as broiling and smoldering. Fast flaming polyurethane is also differentiated from many types of stove top cooking signal profiles. SAIFRA3 Use on products having single photo and one or more heat sensors. The heat sensor is used to further distinguish between fast flaming polyurethane and stove top cooking. SAIFRA4 Use on products having IR and UV multi-criteria chamber. The UV photo detects small particles and is used to further distinguish between fast flaming polyurethane and stove top cooking.