First of all, before fabric inspection machine  running, the fabric will be feeded by hand, and the fabric length from Wheel type Encoder to Rewinder roller(L1) can not be measured, because at this time, the digital counter meter does not start to count. After machine start, the operator will cut the fabric roll by Linear Fabric Cutter, the fabric length from Wheel type Encoder to Rewinder roller(L2) at this time is measured. But Linear Fabric End Cutter cut the fabric at rewinding position, the L2 is remain on the machine, and L2=L1, so the final length measurement is accurate, the error is less than 0.1m/km.