| 摘要 |
<p>An ion detector has a reference chamber 2 and a measuring chamber 1 the latter comprising a first zone 13 wherein is generated ionization by an ???-radioactive source 9, and a second zone 14 wherein are arranged electrodes 5,8 to generate an electric field stronger than the field in said first zone, openings 6,7 being so provided and distributed in the measuring chamber that an air draft reaching the detector will move the ions formed in the first zone towards the second zone, whatever the draft direction. Dimensions are detailed. Plate 4 carries a printed circuit. Electrode 5 may be of stainless steel netting and casing 16 of plastics material. <IMAGE></p> |
