Circuitry for measuring and compensating phase and amplitude differences in NDT/NDI operation

A method of detecting and compensating phased and amplitude differences including a probe generating detecting signals causing a test object to affect characteristics responding signals, in response to the detecting signals, the detecting signals possess a first frequency, the method comprising the steps of:

• a. digitizing the responding signals to a digitized responding waveform using an analog to digital converter;
• b. generating a digitally generated waveform of the first frequency using a digital waveform generator;
• c. converting the generated waveform of the first frequency to generated analog signals of the first frequency and feeding the same back to the probe;
• d. detecting and quantifying differences in phase and amplitude between the responding waveform and the generated waveform of the first frequency using a phase and amplitude detector;
• e. generating a null waveform according to the quantified differences in phase and amplitude using a null waveform generator and converting the null waveform to analog null signals using a digital to analog converter;
• and
• f. nulling the phase and amplitude differences by subtracting the analog null signals from the inspection signals which includes the generated analog signals of the first frequency.

A detection and compensation circuitry for detecting and compensating phase and amplitude differences for an NDT/NDI inspection instrument with an associated probe configured to generate detecting signals causing a test object to affect the characteristics of responding signals in responding to the detecting signals, the detecting signals possess a first frequency, the detection and compensation circuitry comprising:

• an analog to digital converter for converting the received responding signals from analog responding signals to digital responding signals represented by a responding signal waveform;
• at least a first waveform detecting and generating circuit configured to generate a digitally generated waveform of the first frequency, wherein the detecting and generating circuit is also configured to detect phase and amplitude differences between the responding signal waveform and the generated waveform of the first frequency;
• at least a first null waveform generator for generating a first compensating waveform nulling the phase and amplitude differences according to detected phase and amplitude differences;
• and
• a digital to analog converter for converting the first compensating waveform from a digital to an analog compensating waveform and feeding the same to a subtracting circuit to cancel the effect of the phase and amplitude differences.