POSITION-BASED SAMPLING FOR EDDY CURRENT INSPECTION OF STEAM GENERATOR TUBES

摘要

A method of employing an eddy current sensor to perform an inspection of a tube of a steam generator involves accelerating and decelerating the eddy current sensor in a predetermined fashion that substantially reduces the likelihood of damage to the eddy current sensor. The reduction of probe stresses reduces radiological waste and reduces radiation exposure to workers involved in changing damaged probes The recording of an eddy current signal at each of a plurality of equally spaced apart locations along the tube permits the velocity of the eddy current sensor to be varied without compromising the validity of the data that has been recorded. The inspection system employs an encoder that outputs a series of signals as the probe is advanced incremental distances within the tube of the steam generator, and eddy current sensor signals are recorded responsive to at least some of the signals from the encoder.