**4.1.2 Measurement of shed amount**

At the upper state of the heald frame, the distance from the fixed guide of heald frame to the upper line of frame is the amount of upper shedding, the lowest state of the heald frame is the amount of lower shedding.

The warp movement is calculated by the difference between the amount of upper shedding and lower shedding, which is shown in Fig. 5.
