| 摘要 |
<p>A sensor in an air conditioning duct produces a differential pressure signal which varies as a function of the volumetric flow rate of air through the duct. The sensor includes an array of angularly spaced and radially extending arms disposed around and across the duct and each having upstream and downstream sensing tubes formed with ports spaced along their upstream and downstream sides, respectively. Pressure signals are transmitted to the tubes by way of the ports and are averaged by high and low pressure averaging chambers located at the center of the sensor and communicating with the upstream and downstream sensing tubes, respectively. The output signals from the averaging chambers constitute a differential pressure signal which is highly representative of the volumetric flow rate of the air even though the air flows through the duct in an asymmetrical pattern.</p> |
