FBG (fiber Bragg grating) is used as a substitution of electrical strain gauge in port gantry overloading warning system.
A steel rope tension detecting device and FBG load cell were designed, and a rope force calibrating device was used. The force
analysis of tightened steel rope acting on FBG cell, and the process of the measuring data are introduced. The calibration shows that
the sensitivity of the system is around 90 pm/ton, and. it is of good performance, the accuracy and repeatability can be
0.73% in full scale, that is much less than 3%, which is the specification required.