Answer :
Final answer:
Boeing 787 lavatories generally use photoelectric smoke detectors, which detect smoke via light scattering, unlike ionization smoke detectors that involve a radioactive source and ionization of air between electrical plates.
Explanation:
The lavatories on a Boeing 787 are typically equipped with photoelectric smoke detectors. These detectors function by using a light source and a sensor. When smoke particles enter the optical chamber, they scatter the light, which is then detected by the sensor, triggering the alarm. This is different from ionization smoke detectors that use two electrically charged plates and a radioactive source, commonly americium-241 (Am-241), to create a small current. When smoke interferes with the ionization process by obstructing the flow of ions, this alters the current and triggers the alarm. However, the use of radioactive material in ionization detectors and concerns over false alarms have led to the prevalent use of photoelectric detectors in places like aircraft lavatories. Heat detectors and gas detectors are not typically used for the detection of smoke.
