You can buy a separate ionization smoke detector and a separate photoelectric smoke alarm. At most big retail stores, they run about $7 each. Manufacturers also offer dual-technology smoke alarms ...

Ionization detectors are the most common type of alarm. They sense fast-moving, flaming fires. "A flaming fire would be like a kitchen fire… something that flames up quicker," Vassar said.

Ionization smoke alarms are the oldest and most common type to find in a home. They are most effective at detecting open-flame fires, which Covey says were most common decades ago but have been ...

The recall: This recall includes Kidde dual-sensor (photoelectric and ionization) smoke detectors (models PI2010 and PI9010). There were 452,000 sold in the U.S. and 40,000 in Canada.