The use of longitudinal wave UT for detecting, locating, and determining the size of hydrogen blisters is illustrated in Figure 700-17. The blisters are internal…
Tag: Ultrasonic
Figure 700-16 illustrates the use of longitudinal UT for determining the remaining thickness of a corroded shell. If the transducer is placed on a location…
Calibration of longitudinal wave UT consists of developing a “distance amplitude curve (DAC)” for the instrument and transducer, using test blocks manufactured from a material…
Longitudinal wave UT is used primarily to determine the remaining thickness of corroded shell components, including the depth of pits. It can also be used…
Attenuation of ultrasonic waves propagating through air is very high, and normal surface roughness (especially of the workpiece) will always create an air gap between…
Ultrasonic waves for UT are created in a metal workpiece with a piezoelectric transducer that is coupled to the workpiece. The piezoelectric transducer converts high…
Most UT systems used for the in-service inspection of a pressure vessel employ a “pulse-echo” method of operation, in which the same transducer (described below)…