Smoke Detector Testing 

Here's a test of the two First Alert smoke detectors that are installed in my apartment.
Specs of each smoke detector.
1) Brand: First Alert
Model Number: P900
Sensor Type: Photoelectric
Hardwired or Battery: Standard 9V battery
2) Brand: First Alert (originally by BRK)
Model Number: 9120B
Sensor Type: Ionization
Hardwired or Battery: Both hardwired with a 9V battery backup
Note: The first smoke detector that I show is actually mine because the original one, which was a Family Gard smoke detector, was inoperable prior to moving in. So I ended up buying this detector for a reasonable price. Also, the hallway detector does the Code 3 a little bit faster and has a lower pitch to it.

Наука