What feature of ionization smoke detectors allows them to be more sensitive than other detectors?

Ionization smoke detectors are designed to be particularly sensitive to smoke particles, especially those that are small and invisible, which are typically produced by fast-flaming fires. The core principle behind these detectors involves the use of ionization and radioactive material that generates ions in the air. When smoke enters the sensing chamber, it disrupts this flow of ions, triggering the alarm.

This sensitivity to the invisible particles of combustion is what sets ionization smoke detectors apart from other types, such as photoelectric detectors, which are more responsive to larger, visible smoke particles typically produced by smoldering fires. The ability of ionization smoke detectors to detect these smaller particles enables them to respond more quickly to certain fire conditions, making them an effective tool in fire prevention and safety. Thus, their unique mechanism of sensing invisible combustion particles is key to their enhanced sensitivity compared to other fire detection technologies.