The pulse-echo method (ASTM D5882) for pile integrity testing, is based on tapping the pile head using a small handheld hammer and analyzing the resulting head velocities to find length and anomalies. A single impact trace should theoretically contain all the information needed for the analysis. However, a single impact trace may contain any degree of random noise due to environmental noise, poor pile head preparation, or operator errors. Traditionally, a few additional traces were requested, to demonstrate repeatability – the analysis was, nevertheless, done on a single trace.
In contrast, with the Piletest PET (pile integrity test equipment) the operator collects a large number of traces, and the software automatically sorts and averages the impacts while the operator works on the whole set of impact traces as one entity. This approach brings many benefits. Read about, How PET pile integrity test averaging works here