Patent ID: 7417919
Filing Date: 2008-08-26
Classification: G01H,Y10S

Abstract:
1. An apparatus to enable a determination of a distance, R 1 , of a range sensor from a reference plane, the range sensor transmitting pulses and detecting echoes along a pulse-echo path, the reference plane being normal to the pulse-echo path, the apparatus comprising: i) a reference plate with pulse-reflective surface; ii) positioning means to locate the reference plate in the reference plane at a first position on the pulse-echo path, there to reflect pulses back to the range sensor; iii) positioning means to locate the reference plate at a second position on the pulse-echo path at a known distance D from the first position, there to reflect pulses back to the range sensor; and the range sensor incorporating: iv) timing means to determine a time interval, dt v) timing means to determine a time interval, dt vi) computing means to calculate the distance, R