METHOD AND INSTRUMENT FOR MEASURING LENGTH OF BURIED PIPELINE

摘要

PURPOSE: To obtain a method by which the length of a pipeline buried in the ground can be measured with high accuracy without digging the ground over the full length of the pipeline irrespective of the buried direction and material of the pipeline. ;CONSTITUTION: White noise generated from a white noise generator 11 is transmitted into a branch buried pipe 16 from a loudspeaker 12. The noise propagated through the pipe 16 is caught by means of microphones 13 and 14 installed to two points and the length of the pipe 16 is measured by calculating the cross-correlative function between the caught noise signals by means of a correlator 15. By measuring the lengths of the branch pipe 16 to be measured and branch buried pipes 17 and 19 adjacent to the pipe 16, the length of the pipe 16 is measured from the measured results.;COPYRIGHT: (C)1993,JPO&Japio