摘要 |
A gas gauge for sensing distance to an object includes a gas supply system and a nozzle that supplies the gas from the gas supply system to a space between the nozzle and the object. For example, the gas supply system 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 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. Noise generated by the increased flow rate may be attenuated using one or more strategically placed Helmholtz attenuators and/or snubbers.
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