Description

Ionization Smoke Alarm, 9V DC, Without Battery

The Ionization smoke detectors use a small amount of radioactive material, americium-241, to detect smoke. Smoke alarms detect fires by sensing small particles in the air. Once they detect those particles above a certain level, they signal the alarm to sound so that you and your family can get to safety

The sensing part of the Ionization Smoke Alarm detector consists of two chambers – an open, outer chamber and a semi-sealed reference chamber within. Mounted in the reference chamber is a low activity radioactive foil of Americium 241 which enables current to flow between the inner and outer chambers when the detector is powered up. As smoke enters the detector, it causes a reduction of the current flow in the outer chamber and hence an increase in voltage measured at the junction between the two chambers.

Even after the battery has died, the detector maintains a residual charge that will keep the chirp going for at least seven days. To get the device to stop chirping once the battery has been removed, you must drain this residual charge by holding the test button for 15 seconds.

Identify which circuit breaker powers your smoke alarms. Each breaker should be labeled, so look for something that says “smoke alarm” or something similar. Turn off the circuit breaker for your smoke alarms. If your smoke alarms don’t have battery backup, doing that will turn all of them off.

The has the following features:-

• Voice & Location Alerts.
• Interconnected System.
• Safety Path Light.
• First Alert’s Reliable Protection

The Ionization detectors have a different working principle: smoke particles reduce the air ionization, thus triggering the alarm.  All detectors can be evaluated in terms of their various fundamental characteristics, including spectral response, linearity, quantum efficiency, dynamic range, response time, and susceptibility to noise. The radiation emitted from the foil ionises the air in the ISD. An electric voltage applied within the ISD produces an ionisation current. If fire aerosols enter the ISD, the ionisation current changes. This change is detected electronically and is used for setting the alarm.