Frequency tracked gated pulse technique for ultrasonic frequency

US4391142A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• John H. Cantrell · Williamsburg, US
• Joseph S. Heyman · Williamsburg, US

Key dates

• Filing date: Jun 10, 1980
• Grant date: Jul 5, 1983
• Expiry date: Jun 10, 2000

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N29/348
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A tracking generator 21 is slaved to a spectrum analyzer 23 to produce an input signal having a frequency that follows the frequency of the spectrum analyzer sweeping local oscillator 22. The input signal is gated to a transducer 26 by a transmitter gate 25 to produce ultrasonic waves in the sample 28. The resulting ultrasonic echoes are converted into electrical signals by the transducer and then gated into the spectrum analyzer by receiver gate 29. This arrangement produces spectra that are equivalent to shock-exciting the transducer with a true delta function shock-excitation.