Torsional analysis is extremely important in determining the vibratory behavior of rotating systems such as engine driven pumps or generators.
Typically, torsionals have been measured at points along the system by looking at gear teeth (such as the flywheel ring gear) with a magnetic pick up. Points not having a production gear have been measured by either (1) fixing a machined gear to the shaft, or (2) mounting an encoder at the “end” of the system, or (3) utilizing a laser torsional vibrometer.
Read the case study here.