| 摘要 |
<p>A gas gauge (100) for sensing distance to an object (132) includes a gas supply system (102) and a nozzle (128) that supplies the gas from the gas supply system (102) to a space between the nozzle (128) and the object (132). For example, the gas supply system (102) supplies the gas with a flow rate that corresponds to a flow in a transitional region between laminar flow and turbulent flow. A surface of the nozzle (128) may be roughened so as to increase a friction factor across the surface, which increases gas pressure drop and also a gain of the nozzle (128). Noise generated by the increased flow rate may be attenuated using one or more strategically placed Helmholtz attenuators and/or snubbers (120).</p> |
