Accession Number : ADA117841

Title :   Advanced Nondestructive Evaluation (Ultrasonic Pulser/Receiver Technology).

Descriptive Note : Final rept. 29 May 79-1 Feb 81,


Personal Author(s) : Shaufl,Robert A

PDF Url : ADA117841

Report Date : May 1982

Pagination or Media Count : 182

Abstract : The overall goal of this program was to develop a digital ultrasonic correlation system for NDE application of greater versatility and capability than the successful analog system developed in-house at AFWAL/MLLP. SRL had only limited success in meeting this overall goal. The program broke into two complementary tasks: (1) development of an all-digital Pulser/Receiver with a bandwidth of 85 MHz and a maximum gain of 80 dB; and (2) development of a pseudo-random correlation unit. The Pulser/Receiver met all of its necessary requirements; however, the correlation unit suffered from a technical design decision made early in the program as to the number of 'bits' used in the correlation process. The decision (based upon both cost and the results of the computer model of an 8-bit correlation system) was to utilize 1-bit correlation. This choice led to an unavoidable (and most undesirable) nonlinearity in the correlated signal output when the input signal/noise ratio approached unity. This unfortunate consequences has restricted the versatility and capability of the entire system.

Descriptors :   *Ultrasonic tests, *Pulses, *Receivers, *Nondestructive testing, Pseudo noise systems, Test and evaluation, Test equipment, Correlation techniques, Digital systems, Analog systems, Bandwidth, Gain, Requirements, Specifications, Pseudo random systems

Subject Categories : Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE