摘要 |
A method of the operation of an ionization smoke alarm which has a measuring chamber open to the ambient air and ionizable by a radioactive source. A measuring chamber includes a first electrode to which a supply d.c. voltage is applied and a measuring electrode the potential of which changes in response to the smoke density if smoke enters the measuring chamber. This potential is measured for producing a smoke alarm signal if it reaches a predetermined value. The potential of the measuring electrode is measured for at least one further electric field strength that is compared with at least a second potential which occurs at the second field strength according to the law of the agglomeration of small ions if smoke aerosols are present in the measuring chamber.
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