| 摘要 |
Apparatus is described for accurately determining the elevation, E, of a pulse-echo ultrasonic range sensor ( 2 ) relative to a datum level ( 14 ). The figure shows vertical elevations of the apparatus with plate deployed at level-1 ( 12 ) and level-2 ( 13 ) above a datum level ( 14 ), the levels being separated by a known distance, D. The elevation of the sensor is given by the relationship: <?in-line-formulae description="In-line Formulae" end="lead"?>R1=D|(dt1/(dt2-dt1))|<?in-line-formulae description="In-line Formulae" end="tail"?> where dt 1 and dt 2 are the intervals of time, determined by the sensor, taken by a pulse-echo to transit the distances R 1 and R 2 respectively. This apparatus may also be used to determine sonic velocity, Sv from: <?in-line-formulae description="In-line Formulae" end="lead"?>Sv=|2D/(dt2-dt1) <?in-line-formulae description="In-line Formulae" end="tail"?>
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