| 摘要 |
<p>The invention relates to flow detectors capable of detecting relatively small flow rates. The detector generally comprises a flow chamber (12) with an elongate closure element (17) of substantially uniform cross-section pivotally supported in said chamber (12). The pivotal axis for the element (17) is above the center of gravity for the element (17). In a no-flow condition element (17) hangs substantially vertical to close the end of a fluid inlet (18). The flow chamber (12) has such configuration that for the greater part of the displacement of the closure element (17) from a no-flow condition to a full flow condition the flow passage from the inlet (18) to an outlet (22) is around the element (17) and said flow passage has a substantially constant cross-section. In a preferred embodiment an array of sensors (23a to 23d) senses the position of the closure member (17) within the chamber.</p> |
