| 摘要 |
<p>An apparatus for measuring gas pressure comprising a transmitter (18) for transmitting sound waves and a receiver (20) for receiving the transmitted sound waves, the receiver (20) being substantially face-to-face with the transmitter (18) and spaced apart from it by less than or equal included received indicative of the pressure of gas between the transmitter (18) and the receiver (20).</p> |
