| 摘要 |
A system for delivering pulses of a desired mass of gas, including a chamber, a first valve controlling flow into the chamber, a second valve controlling flow out of the chamber. A controller is programmed to receive the desired mass for each pulse through an input interface, close the second valve and open the first valve, receive chamber pressure measurements from a pressure transducer, and close the first valve when pressure within the chamber rises to a predetermined upper level. The controller is also programmed to deliver pulses of gas using just the second valve, wherein, for each pulse, the second valve is opened until a calculated mass for the pulse equals the desired mass for the pulse. The first valve is not required to be opened and closed for each pulse and is, therefore, used less frequently and has an extended life. |
