Title: Security alarm
Content:  quickly detect the small amounts of smoke produced by fast-flaming fires, such as cooking fires or those fueled by paper or flammable liquids. A newer, and perhaps safer, type is a photoelectric smoke detector. It contains a light source in a light-sensitive electric sensor, which is positioned at a 90-degree angle to the sensor. Normally, light from the light source shoots straight across and misses the sensor. When smoke enters the chamber, it scatters the light, which then hits the sensor and triggers the alarm. Photoelectric smoke detectors typically respond faster to a fire in its early, smoldering stage – before the source of the fire bursts into flames.
Title: Smoke detector
Content:   A photoelectric, or optical smoke detector, contains a source of infrared, visible, or ultraviolet light — typically an incandescent light bulb or light-emitting diode (LED) — a lens, and a photoelectric receiver — typically a photodiode. In spot-type detectors, all of these components are arranged inside a chamber where air, which may contain smoke from a nearby fire, flows. In large open areas such as atria and auditoriums, optical beam or projected-beam smoke detectors are used instead of a chamber within the unit: a wall-mounted unit emits a beam of infrared or ultraviolet light which is either received and processed by a separate device or reflected to the receiver by a reflector. In some types, particularly optical beam types, the light emitted by the light source passes through the 
Title: Smoke detector
Content:  being tested, and reaches the photosensor. The received light intensity will be reduced due to scattering from particulates of smoke, air-borne dust, or other substances; the circuitry detects the light intensity and generates the alarm if it is below a specified threshold, potentially due to smoke. In other types, typically chamber types, the light is not directed at the sensor, which is not illuminated in the absence of particles. If the air in the chamber contains particles (smoke or dust), the light is scattered and some of it reaches the sensor, triggering the alarm. According to the National Fire Protection Association (NFPA), "photoelectric smoke detection is generally more responsive to fires that begin with a long period of smoldering". Studies by Texas A&M and the NFPA cited by the 
Title: Smoke detector
Content:  A presentation by Siemens and the Canadian Fire Alarm Association reports that the ionization detector is the best at detecting incipient-stage fires with invisibly small particles, fast-flaming fires with smaller 0.01-0.4 micron particles, and dark or black smoke, while more modern photoelectric detectors are best at detecting slow-smouldering fires with larger 0.4–10.0 micron particles, and light-coloured white/grey smoke. Photoelectric smoke detectors respond faster to fire that is in its early, smoldering stage. The smoke from the smoldering stage of a fire is typically made up of large combustion particles between 0.3 and 10.0 µm. Ionization smoke detectors respond faster (typically 
Title: Smoke detector
Content:   A smoke detector is a device that senses smoke, typically as an indicator of fire. Commercial smoke detectors issue a signal to a fire alarm control panel as part of a fire alarm system. Household smoke detectors, also known as smoke alarms, generally issue an audible or visual alarm from the detector itself or several detectors if there are multiple devices interlinked. Smoke detectors are usually housed in plastic enclosures, typically shaped like a disk about 150 mm in diameter and 25 mm thick, but shape and size vary. Smoke can be detected either optically (photoelectric) or by physical process (ionization). Detectors may use one or both sensing methods. Sensitive alarms can be used to detect and deter smoking in 
Title: Smoke detector
Content:  seconds) to the flaming stage of a fire. The smoke from the flaming stage of a fire is typically made up of microscopic combustion particles between 0.01 and 0.3 µm. Also, ionization detectors are weaker in high air flow environments. Due to this, the photoelectric smoke detector is more reliable for detecting smoke in both the smoldering and flaming stages of a fire. In June 2006, the Australian Fire & Emergency Service Authorities Council, the peak representative body for all Australian and New Zealand fire departments, published an official report, 'Position on Smoke Alarms in Residential Accommodation'. Clause 3.0 
Title: Smoke detector
Content:   An ionization smoke detector uses a radioisotope, typically americium-241, to ionize air; a difference due to smoke is detected and an alarm is generated. Ionization detectors are more sensitive to the flaming stage of fires than optical detectors, while optical detectors are more sensitive to fires in the early smouldering stage. The smoke detector has two ionization chambers, one open to the air, and a reference chamber which does not allow the entry of particles. The radioactive source emits alpha particles into both chambers, which ionizes some air molecules. There is a potential difference (voltage) between pairs of electrodes in the chambers; the 
Title: Smoke detector
Content:  of Palo Alto, California state, "Photoelectric alarms react slower to rapidly growing fires than ionization alarms, but laboratory and field tests have shown that photoelectric smoke alarms provide adequate warning for all types of fires and have been shown to be far less likely to be deactivated by occupants." Although photoelectric alarms are highly effective at detecting smoldering fires and do provide adequate protection from flaming fires, fire safety experts and the NFPA recommend installing what are called combination alarms, which are alarms that either detect both heat and smoke or use both the ionization and photoelectric smoke sensing methods. Some combination alarms may also include a carbon monoxide detection capability. The type and sensitivity of light source and photoelectric sensor and type of smoke chamber differ between manufacturers.
Title: Fire detection
Content: Heat detector ; Smoke detector ; Flame detector ; Fire gas detector Fire detectors sense one or more of the products or phenomena resulting from fire, such as smoke, heat, infrared and/or ultraviolet light radiation, or gas. In dwellings, smoke detectors are often stand-alone devices. In non-domestic buildings, fire detection will typically take the form of a fire alarm system, incorporating one or more of the following automatic devices:
Title: EN 54
Content: EN 54 part 5	Heat detectors - Point heat detectors ; EN 54 part 7	 Smoke detectors - Point smoke detectors using scattered light, transmitted light or ionization ; EN 54 part 10	Flame detectors - Point detectors ; EN 54 part 12	Smoke detectors - Line detectors using an optical light beam ; EN 54 part 20	Aspirating smoke detectors ; EN 54 part 22	Resettable line type heat detectors ; EN 54 part 26	Point fire detectors using carbon monoxide sensors ; EN 54 part 27	Duct smoke detectors ; EN 54 part 28	Non-resettable line-type heat detectors ; EN 54 part 29	Multi-sensor fire detectors - Point detectors using a combination of smoke and heat sensors ; EN 54 part 30	Multi-sensor fire detectors - Point detectors using a combination of carbon monoxide and heat sensors ; EN 54 part 31	Multi-sensor fire detectors - Point detectors using a combination of smoke, carbon monoxide and optionally heat sensors 

Question: which type of fire detector uses the effect of smoke on a light source and photo-electric cell?
Answer: optical smoke detector.