METHOD AND DEVICE FOR TESTING THE MATERIAL OF A TEST OBJECT IN A NONDESTRUCTIVE MANNER.

摘要

The invention relates to a method for testing the material of a test object (8) in a nondestructive manner, said test object being moved relative to a probe (1) at a variable relative speed. The method has the following steps: detecting a probe signal (US) using the probe (1); converting the probe signal (US) from analog to digital in order to generate a digitized probe signal (USD) in the form of a sequence of digital words with a specified, in particular constant, word repetition frequency; decimating the word repetition frequency of the digitized probe signal (USD) or a digital demodulation signal (UM) derived from the digitized probe signal in n stages using n cascaded decimating stages (5_1 to 5_n), wherein n ≥ 2; selecting an output signal (UA_1 to UA_n) of one of the n decimating stages (5_1 to 5_n) dependent on the current relative speed; and filtering the selected output signal using a digital filter (7) that is clocked at the word repetition frequency of the selected output signal.