METHOD AND CIRCUITRY FOR REMOVING CIRCLING DRIFTS IN NDT/NDI MEASUREMENT DISPLAY

摘要

Disclosed is a method and an apparatus for removing circling drifts on the display of the measured eddy current or other continuous waves. The circling dot which is supposed to be a static dot can obscure information required by the operator to judge if a small defect is present. Embodiments of presently disclosed harmonic rejection filters are tunable and employed to effectively abate or eliminate signals with frequencies that are multiples of operating frequencies, resulting in the removal of the circling effects on the display.

主权项

1. A circuitry configured for processing digitized measurement input data for a non-destructive testing and inspection (NDT/NDI) instrument, the instrument is configured to operate at an operating frequency, chosen from a plurality of possible operating frequencies, the digitized input data including data of the operating frequency, the circuitry comprises,
at least one filtering channel receiving the digitized input data and producing a first set of filtered data, a data processor processing the filtered data and preparing display data containing measurement result for display, and a display unit displaying the measurement result according to the display data, wherein the filtering channel including a first harmonic rejection filter which is configured to substantially abate amplitude of the first set of filtered data at the operating frequency and frequencies which are multiples of the operating frequency.