| 摘要 |
<p>The ionisation gas or smoke detector, for use in public building etc., responds to the detection of smoke fumes or gas, to actuate an alarm circuit. Two ionisation chambers are connected in series and supplied via a direct current source with electronic visualisation and signalling means for the detected gas etc. Prefererably the two ionisation chambers (7, 23) comprise a closed reference chamber (7) and a detection chamber (23) communicating with the environment the dividing wall between the two chambers (7, 23) acting as the common positive electrode for both chambers. The negative electrode in the detection chamber (23) may be formed by a rotatable disc (12) allowing the volume of the chamber to be regulated.</p> |
