In case of the system which is assembled on rotating shaft, some mechanical forces affect to a system.
Therefore mechanical stamina of the system has to be take under consideration. Because of high rotation
speed, weight of the on shaft unit needs to be balanced, so that attaching measurment system will not cause
additional vibration. Wiring terminals of strain gauges are fragile part of element. Since they are often
without cover, external stress may cause failure. Furthermore conventional strain gauges are difficult to
align.