smoke detectors

FDS (ion)

The FDS series ionization smoke detectors offer a high standard of performance and quickly respond to visible and invisible combustion products generated by fire in its incipient stage. They are suitable for a wide range of applications in office buildings, hotels, etc. The operating principle of these detectors are as follows. Basically, the ionization smoke detector consists of an open sampling chamber(i.e. accessible to ambient air), a sealed reference chamber and electronic circuit for alarm evaluation. Air in both ionization chambers is ionized by small amount of americium 241, and with D.C. voltage applied to the electrodes, a weak electric current flows within the inonization chambers. When combustion products enter the sampling chamber, the current falls and the sampling chamber voltage rises, whereby the reference chamber voltage falls. This disturbance of the balance between the two ionization chambers is evaluated by means of the electronic circuit as an alarm signal, which is transmitted to the control panel.

FEATURES
- Conventional type
- Small monitoring current of 45pA
- 02-wire system
- Alarm response lamp (LED)
- Voltage stabilizer
- Simple mounting
- Low profile
- Non-alarm verification type
- Approved by Japan Fire Equipment Inspection Institute