摘要 |
<p>A gas dosing device for medical apparatus uses electrical control signals for connecting a gas supply under pressure through a pressure reducer to an outlet which is connected to the use load for the gas. The device includes a buffer connected between the gas source and the outlet and a reversing valve connected to the buffer and to the outlet. A pressure valve connected to the buffer and to the outlet. A pressure chamber is connected to the buffer and a measuring chamber is connected to the reversing valve. A differential pressure transducer has one connection to the pressure chamber and another to the measuring chamber and thus receives a differential of the pressure between these chambers. A control is connected to the reversing valve and to the differential pressure transducer and in accordance with the pressure which it senses in that transducer it shifts the reversing valve so that it shifts the connection of the measuring transducer to the buffer to a connection of the measuring chamber to the outlet in accordance with the pressure in the pressure transducer.</p> |