Patent ID: 6388439
Filing Date: 2002-05-14
Classification: G01B,G01N

Abstract:
Method for measuring a gap separating a vault of at least one end fitting and a given element of one end of a terminal part of a pipe, the method comprising the steps of:moving at least two measuring devices along the inside of the pipe, each said device comprising a respective high resolution eddy-current sensor, said at least two sensors being mounted on a common support, said support being movable inside and along the pipe, the sensors being spaced from one another on said support by a fixed distance E; carrying out at least one series of measurements during the movement of the measuring devices in the end fitting, the measurements comprising the steps of: detecting in real time with each of said sensors the passage of a pair of consecutive spatial transitions defined respectively by the vault of the end fitting and the end of the terminal part of the pipe; triggering the measurements for a predetermined time between the detections of said transitions; storing the measurements in the form of signals in at least one memory; and processing the stored signals in order to determine a time offset &Dgr;T between detection of a given transition by the two sensors and a time T1 or T2 taken by one of said sensors to run a gap D between the two consecutive transitions, and to determine from the values thus obtained and from said fixed distance E, the value of said gap separating said two consecutive transitions.