Automatic fire detection systems can be made very sensitive to detect genuine fires. But in the practical application they often suffer from unacceptable high false alarm rates that are due to detector deception in about 50% of the cases. To improve the situation it is necessary to use as much information contained in the sensor signal of the detector head as possible. Modem software controlled electronics offer the opportunity to implement even more sophisticated signal processing algorithms and to apply them in practical installations. So the development of effective detection algorithms that are dedicated to fire detection problems becomes increasingly interesting. The contribution deals with fundamental features that can be observed in sensor signals from fire detector heads in practical installations and with the development of detection algorithms based on these observations. Several different proposals recently made in the literature are discussed. Single sensor based fire detection SSbFD) as well as multiple sensor based fire detection (MsbFD) is mentioned. In the MSbFD case spot type MSbFD-systems and space type MSbFD-systems are considered. The chances for an application of fire detection algorithms of the discussed type in commercial applications depend very much on the possibility of testing the new systems with an acceptable expenditure of time and money.