Optical smoke detectors are ideal at detecting visually smoky fires which are likely to be slow fires. Accommodated with red LED fire indicator.Ionization sensor smoke alarms contain a small amount of radioactive material, americium embedded in a gold foil matrix within an ionization chamber. The matrix is made by rolling gold and americium oxide ingots together to form a foil approximately one micrometer thick. This thin gold-americium foil is then sandwiched between a thicker (~0.25 millimeter) silver backing and a 2 micron thick palladium laminate.
This is thick enough to completely retain the radioactive material, but thin enough to allow the alpha particles to pass.
