New possibilities of increasing accuracy for nondestructive testing: Part 1. Basic principles and application examples

A new method for increasing accuracy of nondestructive testing techniques, particularly electromagnetic (eddy current), thermal, electrical, capacitance, etc., is proposed. The method, called a testing methodology by calibrated disturbing factors, is based on recording of a measuring instrument's response to the introduction of calibrated disturbing excitations in the active testing area. Analysis of the recorded response provides the possibility to calculate corrections for measurement results, to supplement data processing algorithms with corrective actions and to identify sources of measurement uncertainties. In comparison with conventional calibration techniques, the proposed method is based on calibration of disturbing influences in a range available for the calibration experiment with necessary accuracy and transformation of calibration results to the range of real testing conditions not directly accessible. Several data processing algorithms are proposed for calculation of measurement corrections. This series of papers devoted to the subject of calibrated disturbing factors comprises three parts. The first part, this particular paper, has an introductory character and is devoted to explanation of basic principles of the proposed testing methodology. In the second part, data processing algorithms and, in the third part, analysis of data processing algorithms as well as accuracy tests will be described.