Patent ID: 8907828

Claim:
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, comprising the following steps: detecting a probe signal (US) by means of the probe subjecting the probe signal (US) to analog-to-digital conversion in order to generate a digitized probe signal (USD) in the form of a sequence of digital words with a predefined, in particular constant, word repetition rate, n-stage decimation of the word repetition rate of the digitized probe signal (USD) or of a digital demodulation signal (UM) derived from the digitized probe signal, wherein the n-stage decimation is performed by means of n cascaded decimation stages ( 5 _ 1 to 5 _n), where n≧2, selecting an output signal (UA_ 1 to UA_n) of one of the n decimation stages ( 5 _ 1 to 5 _n) depending on the instantaneous relative speed, and filtering the selected output signal by means of a digital filter ( 7 ), which clocked with the word repetition rate of the selected output signal.