| 摘要 |
A sensor apparatus particularly for borehole or other remote location use can measure multiple parameters with no electronics in the apparatus and only a single conductor cable. Double-ended tuning forks 26, 28 and 38, 40 in the head are arranged to respond to different parameters such as temperature and pressure by adjusting their resonant frequencies. A drive signal on the conductor 50 is applied to transducers 30, 32, 42, 44 on all the tuning forks and those whose instantaneous resonant frequency is close will resonate. The signal is removed and the transducers return a decaying signal at the resonant frequency along the conductor. Other drive frequencies are tried, to locate the other sensors whose frequency ranges are separate.
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