Most people are familiar with the beeping sound of a smoke alarm, but not everyone knows that there are actually three different types of smoke detectors. The most common type is the ionization smoke detector, which uses a small amount of radioactive material to create an electrical current. This current helps to detect the presence of smoke particles in the air, and the alarm is activated when the level of particles reaches a certain threshold.nnAnother type of detector is the photoelectric smoke detector, which uses a light source to detect the presence of smoke particles. This type of detector is more sensitive to smouldering fires and is less likely to produce false alarms. Finally, there are dual-sensor smoke detectors, which combine both ionization and photoelectric sensors. These detectors provide the highest level of protection against both slow-burning and fast-burning fires.