The ULTRA SON computer program is designed for use in precise ultrasonic contact scan measurements for nondestructive characterization of materials. This program performs major functions necessary for controlling an ultrasonic apparatus, analyzing the measurement data generated by the apparatus, and displaying the results of the analysis. Written in the LabVIEW programming language, ULTRA SON is intended to supplant older ultrasonic-testing programs that are difficult to use and that require large computers: ULTRA SON is user-friendly and can be executed on personal computers.

One of the ULTRA SON Displays is a window containing a raw time-domain waveform (ultrasonic-transducer voltage vs. time). This display prompts the user to enter the times when the front- and back-surface echoes are considered to begin and end ('B2' denotes the second back-surface echo), the voltage sensitivity level for the display, and the voltage offset control to enable calculation of frequency-based properties. The user can also specify the type of time-domain signal-processing window.
For a given specimen to be characterized, ULTRA SON guides the user by generating an interactive display (part of a LabVIEW "Virtual Instrument") that contains a sequence of buttons and windows through which the user sets the parameters of the sequential measurement, analysis, and display operations pertaining to that specimen. The user provides input via a keyboard, a mouse, or both. The figure presents an example of an ULTRA SON interactive display.

ULTRA SON provides for analog-to-digital conversion at a sampling rate up to ≈ 1 GHz. Once a set of ultrasonic-echo data for a specimen has been acquired, ULTRA SON processes the data to calculate the ultrasonic properties that are often used to characterize the bulk nonultrasonic physical properties and microstructure of the specimen. These ultrasonic properties include the following:

  • The phase velocity and the attenuation coefficient, both as functions of frequency;
  • Reflection coefficients;
  • Cross-correlation velocity;
  • Peak frequencies, bandwidths, durations, rise times, fall times, slew rates, and overshoots of pulses; and
  • Magnitude, phase, and power spectra.

In this program, with the exception of power spectra, ultrasonic properties are calculated on the basis of magnitude (as opposed to power) frequency-domain spectra.

ULTRA SON is written for use on a personal computer with a minimum recommended '586 processor operating at a speed of at least 133 MHz and running the Windows 95 or Windows NT4.0 operating system. A Sonix, Inc., STR*81g card (which contains a 1-GHz analog-to-digital converter) and the associated software must be installed in the computer. The user-interface part of ULTRA SON is designed for a video monitor with a resolution of 1,024 × 768 pixels and a size of at least 20 in. (51 cm).

This program was written by Don J. Roth and Wei Cao of Glenn Research Center and Kevin Furrow of Sonix, Inc. For further information, access the Technical Support Package (TSP) free on-line at www.nasatech.com/tsp  under the Physical Sciences category.

Inquiries concerning rights for the commercial use of this invention should be addressed to

NASA Glenn Research Center
Commercial Technology Office
Attn: Steve Fedor
Mail Stop 4 — 8
21000 Brookpark Road
Cleveland
Ohio 44135.

Refer to LEW-16703.


NASA Tech Briefs Magazine

This article first appeared in the February, 2000 issue of NASA Tech Briefs Magazine.

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