QuickFFT

QuickFFT (QFFT) is an ultrasonic transducer evaluation package to test ultrasonic transducers and print certificates. The package includes a PR300 pulser/receiver card, an AD100 100MHz analog to digital converter card, and a program called QFFT. The two PC cards are compatible with PCs 386Mhz or higher; the QFFT program runs under Windows 3.1, 95, and 98.

The PR300 generates an electrical pulse with user defined pulse voltage and pulse width. The pulse is transmitted to an ultrasonic transducer, which converts the electrical excitation pulse to an ultrasonic pulse. The pulse is then propagated into couplant or the material to be tested. In pulse-echo mode operation, the transmitting transducer receives echoes that are reflected from an interface. In transmission mode, a second transducer receives the ultrasonic pulse. In both modes, the receiving transducer converts the ultrasonic pulse back into an electrical signal after it has propagated through the material, and the PR300 receiver processes the signal with the user-defined parameters. The processed signal is digitized by the AD100 card.

The QFFT program analyzes the digitized signal with the method of Fast Fourior Transform. It ascertains the peak frequency, -6dB upper frequency, -6dB lower frequency, the center frequency, and the bandwidth; and displays the results on the screen. A user can specify the title of the certificate as well as other parameters, such as transducer properties, instrument types, and the color of the traces.