This document is about the operation manual of the HLN-11 series of Leeb hardness tester of the Times. It details the names, performance and applications of the hardness tester, testing principles, pre-treatment of test pieces, use and operation, maintenance, several issues affecting test accuracy, fault analysis and maintenance, non-maintenance spare parts list, standard Lede hardness block, Leeb hardness tester and repair and calibration services.