Design and analysis of indentation tester with nanometer accuracy

Based on the instrumented indentation technique, an indentation tester with nanometer accuracy, which integrate the functions of driving, measuring, controlling and data-analyzing together, is presented in this paper. The test´s intermediate error is decreased by loading with voice coil actuator without transmission mechanism And the signal is acquired from high-precision capacitive displacement sensor and strain gauge load cell. An closed loop control system based on PID algorithm is developed and control software is programmed. By analyzing the displacement influence factors, calibrating the instrument compliance and confirming the initial contact point, the accuracy of the testing result is guaranteed sufficiently.