Smoke Detector Facts

Invention

• The smoke detector was invented in 1890 by Francis Robbins Upton.

Power Source

• Most smoke detectors are battery-operated, but others are wired directly into a building's electrical system. Public-safety campaigns often recommend changing or testing your smoke detector battery when the time changes in areas that have Daylight Saving Time.

Detection Methods

• Smoke detectors generally detect the presence of smoke in one of two ways. Ionizing smoke detectors work by detecting smoke particles that are too small to be seen. Optical smoke detectors use light to detect smoke. Some smoke detectors utilize both techniques.

Replacement

• The National Fire Protection Agency recommends replacing your smoke detectors every 10 years, because they can become less reliable over time. Smoke detectors should also be cleaned occasionally to remove any buildup of dust.

Laws

• Most states and municipalities have laws that dictate how many smoke detectors residences and other buildings must have and where they must be placed. In the United States, laws generally require a smoke detector on every level of a home and near all bedrooms.