Torque Measurement by Pointer and Scale

Suppose the angle of twist on the shaft due to application of torque T is θ, which can be directly read by pointer and scale (Figure 18.15). The value of torque applied is directly related to angle of twist as

Figure 18.15 Torque Measurement by Pointer and Scale

where L is the length of the shaft; J is polar moment of inertia; and G is modulus of rigidity of shaft material. J is function of shaft diameter