TB 42 Single Station Smoke Detectors

Question 1

TB 42 Single Station Smoke Detectors

The chamber detects products of combustion by one of two methods—photoelectric or ionization.

Answer 1

reference

Question 2

TB 42 Single Station Smoke Detectors

In the photoelectric smoke detector, a light source projects a beam of light across a darkened chamber within the detector. When smoke enters the chamber, the light striking the smoke is scattered in the same way that auto headlights are scattered by fog. When sufficient light is scattered onto the photocell, the alarm is sounded.

Answer 2

reference

Question 3

TB 42 Single Station Smoke Detectors

Ionization detectors use a minute amount of radioactive material to ionize the air between two interior electrodes conducting a small electric current. Invisible particles that enter the ionized detector chamber reduce the flow of current, finally break the current flow, and then set off an alarm.

Answer 3

reference

Question 4

TB 42 Single Station Smoke Detectors

Results of these tests strongly point to photoelectric detectors being more reliable in warning against the hazards of visible smoke build-up from the slow smoldering fire so common to residential occupancies. Photoelectric detectors appear to be less prone to unwarranted nuisance alarms.

Answer 4

photoelectric

Question 5

TB 42 Single Station Smoke Detectors

Photoelectric detectors are more sensitive to smoldering fires, ionization to flaming fires.

Answer 5

reference

Question 6

Department of Water and Power stating that the average residence is without power only ____ minutes per year.

Answer 6

three