1. After the measurement, the chain is cleaned;
2. The chain to be tested is placed on the two sprockets, and the upper and lower sides of the tested chain should be supported;
3. The chain before the measurement should be stopped for 1 min under the condition of applying one-third of the minimum ultimate tensile load;
4. When measuring, apply the specified measuring load on the chain to tension the upper and lower chains, and the chain should ensure normal toothing on the sprocket;
5. Measure the center distance between the two sprockets.