Chain length accuracy should be measured and visually inspected according to the following requirements

1. The chain is cleaned before measurement

2. Wrap the chain to be tested on the two sprockets, and the upper and lower sides of the chain to be tested should be supported

3. The chain before the measurement should stay for 1 min under the state of applying one-third of the minimum ultimate tensile load

4. When measuring, apply the specified measurement load on the chain to make the upper and lower chains tensioned. The chain and the sprocket should ensure normal meshing

5. Measure the center distance between two sprockets

Measuring chain elongation

1. In order to remove the clearance of the entire chain, it is necessary to measure under a certain degree of pulling tension on the chain

2. When measuring, in order to minimize the error, measure at 6-10 knots (link)

3.测量节数的滚子之间的内侧L1和外侧L2尺寸,以求出判断尺寸L=(L1+L2)/2

4. Find the elongation length of the chain. This value is compared with the limit value of chain elongation in the preceding item. Chain elongation = judgment size - reference length / reference length * 100%, reference length = chain pitch * knot number

Visual inspection of chains

1.Whether the inner/outer chain piece is deformed, cracked or embroidered

2. Whether the pin is deformed or rotated, embroidered

3. Whether the roller is cracked or damaged. Excessive wear

4. Whether the joint is loose and deformed

5. Whether there is abnormal noise or abnormal vibration during operation, and whether the chain lubrication is in good condition