| 摘要 |
<p>Apparatus and a method for precision batch or continuous flow blending of gases are described. Pulsatile precision gas metering valves (15a-15d) having essentially zero dead space are employed to introduce gases to a mixing chamber (20) in predictable uniform quantities to achieve precision gas blends according to predetermined criteria. During batch processing, gases to be blended are repeatedly characterized by the change in mixing chamber (20) pressure with respect to time immediately after blending. Estimates of additional amounts of a given gas to be added to achieve a desired final partial pressure of the given gas in the mixing chamber (20) are based on empirical data previously measured and stored for the gas in question.</p> |
