Operating anaesthetic vaporiser for low boiling point narcotics - using control unit to cool vaporising chamber so that internal pressure drops below that in narcotic gas duct

摘要

In the null setting the vapouriser is bridged by a diversion path so that fresh gas can be fed directly into the anaesthesing appts. to bring the internal pressure of the vapourising chamber (7) below that pertaining in the narcotic gas duct (15), the chamber is cooled down and then a connection is made between the narcotic gas duct or the surroundings and the vapourising chamber via a switching element (21). The switching element (20) at the by-pass (5) is then opened. The switching element (21) at the junction (14) is connectable to the surroundings via ventilation sockets. A control unit (25) has a signal processor (26) connected to a differential pressure pick-up (28) for processing a pressure signal from an internal pressure sensor (24) in the vapourising chamber. ADVANTAGE - Prevents increased delivery of narcotic gas to fresh gas at initiation of vapouriser.