Method and apparatus for performing ultrasonic flaw detection by controlling peak frequency and frequency bandwidth

A method of performing ultrasonic flaw detection, comprising the steps of:

• outputting a pulse signal having a carrier frequency and a cycle count, both of which are designated, to an ultrasonic probe attached to an object to be tested and causing an ultrasonic wave to be incident on the object;
• causing said ultrasonic probe to receive a reflected wave of the ultrasonic wave incident on the object to obtain an echo signal;
• changing the cycle count of the pulse signal so that a frequency bandwidth of the received echo signal becomes a predetermined bandwidth;
• changing the carrier frequency of the pulse signal so that a peak frequency of the received echo signal becomes a predetermined frequency;
• and
• detecting a defect present in the object in accordance with the echo signal output from said ultrasonic probe.

A method of performing ultrasonic flaw detection, comprising the steps of:

• outputting a pulse signal having a carrier frequency and a cycle count, both of which are designated, to an ultrasonic probe attached to an object to be tested and causing an ultrasonic wave to be incident on the object;
• causing said ultrasonic probe to receive a reflected wave of the ultrasonic wave incident on the object to obtain an echo signal;
• changing the carrier frequency of the pulse signal independently of a frequency bandwidth of the echo signal so that a peak frequency of the echo signal becomes a predetermined frequency;
• changing the cycle count of the pulse signal independently of the peak frequency of the echo signal so that the frequency bandwidth of the echo signal becomes a predetermined bandwidth;
• and
• detecting a defect present in the object in accordance with the echo signal output from said ultrasonic probe.

An apparatus for performing ultrasonic flaw detection, comprising:

• ultrasonic transmitting means for outputting a pulse signal having a designated carrier frequency and a designated cycle count,
• ultrasonic probe means, attached to an object to be tested, for outputting an ultrasonic wave to the object in response to the pulse signal input from said ultrasonic transmitting means and for outputting an echo signal,
• ultrasonic receiving means for receiving the echo signal output from said ultrasonic probe means,
• signal analyzing means for detecting a peak frequency and a frequency bandwidth of the echo signal received by said ultrasonic receiving means, and
• transmission control means for designating the carrier frequency and the cycle count of the pulse signal output from said ultrasonic transmitting means so that the detected peak frequency and the detected frequency bandwidth become a predetermined peak frequency and a predetermined frequency bandwidth, respectively.

An apparatus for performing ultrasonic flaw detection, comprising:

• ultrasonic transmitting means for outputting a pulse signal having a designated carrier frequency and a designated cycle count,
• ultrasonic probe means, attached through an ultrasonic wave propagation medium to an object to be tested, for outputting an ultrasonic wave to the object in response to the pulse signal input from said ultrasonic transmitting means and for outputting an echo signal,
• ultrasonic receiving means for receiving the echo signal output from said ultrasonic probe means,
• signal analyzing means for detecting a peak frequency and a frequency bandwidth of the echo signal received by said ultrasonic receiving means,
• flaw detection condition memory means for storing a flaw detection condition peak frequency and a flaw detection condition frequency bandwidth of the echo signal, and
• transmission control means for designating the carrier frequency and the cycle count of the pulse signal output from said ultrasonic transmitting means so that the detected peak frequency and the detected frequency bandwidth become the stored flaw detection condition peak frequency and the stored flaw detection condition frequency bandwidth, respectively.