THERE ARE TWO BASIC SMOKE ALARM TYPES - IONIZATION AND PHOTOELECTRIC.
Ionization smoke alarms (such as this Smoke Alarm) are your best overall choice
for reliability and fast response time, since they quickly sense small
"invisible" smoke particles and will also sense larger "visible" smoke
particles. Photoelectric smoke alarms may respond more quickly in certain types
of fires, for example - slow smoldering fires with large "visible" smoke
particles. ALL TYPES OF SMOKE ALARMS HAVE LIMITATIONS. NO TYPE OF SMOKE ALARM
CAN SENSE EVERY KIND OF FIRE OR SMOKE EVERY TIME.