The Investigators: Get Out Alive - WMC Action News 5 - Memphis, Tennessee

The Investigators: Get Out Alive

By Andy Wise - bio | email

MEMPHIS (WMC TV) - Smoke detectors come in two's:

* PHOTOELECTRIC:  "Photoelectric detectors are more designed for detecting smoldering fires," said Graham McBride, detector expert with State Systems (, a Memphis-based company that specializes in commercial fire protection systems.

"A photoelectric detector uses a light beam to detect smoke," McBride said.

* IONIZATION: "An ionization detector uses a radioactive element to ionize the air," McBride said. "It, in turn, detects small particles of smoke that are not visible to the naked eye.

"Ionization detectors do a better job of detecting flaming fires which contain smaller particles."

McBride said that's why the ionization detector detected the smoke twenty seconds faster than the photoelectric detector in our test with the Memphis Fire Department.

"(The firefighters) used a propane torch to ignite the hay," he said. "The hay emitted a significant amount of smoke.

"The characteristics of a fast burning, flaming fire (smaller smoke particles) were present before the characteristic of a slow burning smoldering fire (large smoke particles). Thus the ionization detector went into alarm prior to the photo detector."

Other tests like the one the Action News 5 Investigators conducted have demonstrated the photoelectric detector reacting more quickly than the ionization detector, like this test by television station KXLY in Spokane, WA:

"The slow-burning, smoldering fire (in KXLY's) test was ignited with a soldering iron," said McBride. "This allows the smoke to build before the flames."

Lt. Wayne Cooke, public information officer for the Memphis Fire Department, said the department does not endorse either type of detector. What firefighters do endorse, he said, is a working and maintained smoke detector near every bedroom.

"To put them in every sleeping area in your home," Cooke said, "and maintain that working smoke detector in your place of residence."

A firefighter's rule of thumb is to change the batteries in each smoke detector every time you adjust your clocks to daylight-saving time or to standard time.

March 28, Carolyn Hinton and her family of nine escaped their burning rental home in the Walker Homes neighborhood of South Memphis. Fire investigators determined faulty electrical wiring in one of the children's bedrooms started the fire, which resulted in a total loss of the home and the Hintons' belongings.

Hinton said a working and maintained smoke detector, installed high on a wall in the middle of the bedroom hallway, alerted the family in plenty of time.

"If we didn't have a smoke detector that night, we all would have died," she said.

The fire destroyed the detector. Hinton doesn't know for sure what type it was, but she said the fire started quickly and hot, with flames lapping a mattress. She said based on the type of fire it was, she suspects the detector was an ionization detector.

"The smoke detector saved our lives that night," she emphasized. 

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