| 摘要 |
In a gas gauge, effects due to changes in the local environment are reduced by causing a measurement nozzle and a reference nozzle to react as if they were co-located, or located at approximately the same position. This is achieved by venting the reference nozzle in very close proximity to the measurement nozzle. A reference chamber surrounding the reference plate and reference nozzle is vented at approximately the same location as the measurement nozzle. In an embodiment for use in a vacuum environment, the measurement nozzle is surrounded with an annular ring. The measurement annular ring is connected to an annular ring around the reference nozzle, which acts to co-locate the reference nozzle and the measurement nozzle. To avoid choked flow, another annular ring or rings may be placed around the measurement annular ring.
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