Photoelectric Smoke Detectors

When it comes to home safety for your family, smoke detectors should always be placed and maintained around your house.

There are two main types of smoke alarms, photoelectric smoke detectors and ionization smoke detectors. This hub will concentrate on photoelectric detectors.

What are Photoelectric Detectors

There are two types of photoelectric devices, in the first device there is a beam of light, if smoke stops the light reaching a photocell within the device an alarm is sounded.

The second and more common type of photoelectric sensor has a T-shaped compartment which contains an LED light that fires a beam of light across the horizontal part of the compartment. A photocell, which is seated at the bottom of the vertical base of the compartment, generates a constent current when exposed to light. As long as the compartment remains smoke free the the light passes across the top of the T in a straight line, not striking the photocell. However if smoke enters the compartment, it causes the light to scatter and pass down to hit the photocell. When a certain degree of light hits the cell an alarm is sounded.

A photoelectric smoke detector is designed to be quick at detecting particulate smoke generated by smoldering fires rather than high intensity flaming fires which tends to make them less sensitive to false alarms from cooking vapour or steam from the kitchen or bathroom than that of ionization smoke alarms.

Both types of detectors have been tested and certified to be used within the home. If you are not sure which type to get, you could install several of each type just to be sure.