HIGH-PRECISION MEASURING METHOD AND APPARATUS

摘要

A method of measuring a predetermined parameter having a known relation to the transit time of movement of an energy wave through a medium, comprising: transmitting (2) from a first location (A) in said medium a cyclically- repeating energy wave; receiving (3) said cyclically-repeating energy wave at a second location (B) in said medium; detecting a predetermined fiducial point in the cyclically-repeating energy wave received at said second location; continuously changing the frequency of transmission of the cyclically-repeating energy wave from said first location to said second location in accordance with the detected fiducial point of each cyclically- repeating energy wave received at said second location such that the number of waves received at said second location from said first location is a whole integer; and utilizing the change in frequency to produce a measurement of said predetermined parameter. 2239 י" ד באלול התשס" ד - August 31, 2004