This guide was prepared to assist field foresters in the use of stress wave timing instruments to locate and define areas of decay in standingtimber. The first three sections provide background information, the principles of stress wave nondestructive testing, and measurement techniques for stress‍?wave nondestructive testing. The last section is a detailed description of how to apply stress wave nondestructive testing methods to standing timber. A sample field data acquisition form is included.

Stress-wave nondestructive evaluation (NDE) techniques are used widely in the forest products industry--from the grading of wood veneer to inspection of timber structures. Inspection professionals frequently use stress-wave NDE techniques to locate internal voids and decayed or deteriorated areas in large timbers. Although these techniques have proven useful, little information exists concerning the relationship between stress-wave parameters and deterioration observed as a consequence of marine borer attack. In this pilot test, we examined the relationship between stress-wave transmission time and the quality of wood in Sitka spruce and western hemlock logs that had varying degrees of deterioration as a consequence of attack from marine borers. Stress-wave transmission time, perpendicular to grain, was measured at several locations on each log. The logs were then sawn into lumber, which was then visually evaluated. A relationship was observed between stress-wave transmission time and deterioration of the logs and the yield of lumber from the logs.

This book was proposed and organized as a means to present recent developments in the field of nondestructive testing of materials in civil engineering. For this reason, the articles highlighted in this editorial relate to different aspects of nondestructive testing of different materials in civil engineering—from building materials to building structures. The current trend in the development of nondestructive testing of materials in civil engineering is mainly concerned with the detection of flaws and defects in concrete elements and structures, and acoustic methods predominate in this field. As in medicine, the trend is towards designing test equipment that allows one to obtain a picture of the inside of the tested element and materials. From this point of view, interesting results with significance for building practices have been obtained