While reasonably satisfactory methods exist for nondestructively determining t he presence or absence of an adhesive bond, no method exists for nondestructively determining the strength of what appears to be a good bond. Bonds that do not attain their full strength can be caused by a thin layer of contaminant , improper surface roughness, and a variety of other surface phenomena that are difficult to detect by conventional methods.l,2,3 One technique is to use an ultrasonic pulse to investigate the bond interface. Since the amplitude of the pulse reflected by t he bond interface is a f unction of the elastic properties of the bond, i t should be possible to correlate t he absolute ultrasonic reflectivity with t he bond strength.