| 摘要 |
In an electronic smoke sensing and alarm device, a dual ionization chamber arrangement comprises a single source of radioactive material and first and second chambers separated by a common electrically conductive electrode. A portion of the radioactive material ionizes the air in the first chamber and another portion of the radioactive material ionizes the air in the second chamber. This arrangement provides an accurate control on the current flow through each chamber. A single source 36 of radioactive material, eg. Americium 241 or Nickel 63, may be disposed on a support 38 which is located on the partition 16 separating the two chambers 28 and 30 so that approximately the same amount of radioactive material is exposed in each chamber. The source and its support may be various shapes. Alternatively, the partition itself may be made up of a radioactive substance. <IMAGE> |
