Ultrasonic Reference Blocks and Characterized Fatigue Cracks
The National Bureau of Standards initiated an identifiable program in nondestructive testing about a year and a half ago. Up until that time there was significant effort in areas affecting NDT, but the focus of these efforts was not nondestructive testing.
I will describe only a couple of the facets of the current NOT program at NBS. The program is growing, and by now is approaching the size of about 3/4 of a million dollars per year. The aim of the program is to bring direct impact on nondestructive activities through better test methods, through standards, and through measurement services and interpretive methodologies.
I will describe progress on an activity aimed at near term improvements in ASTM type reference blocks and also on an effort aimed at producing characterized flaws. I will also very briefly touch on some work we are doing towards establishing measurement techniques for determining the characteristics of ultrasonic and acoustic emission transducers. The ASTM reference block work is supported by the Air Force, NASA and the Army, and the work on characterized flaws and transducers is supported by in-house funding.