Force acquisition system for digital impact tester

A force acquisition system for digital impact tester was investigated, in which structural design of bar-shaped elastic element, circuit design as well as static analysis were involved. Based on analysis of international requirements on the detection precision of digital impact tester, information concerning the precision of sensor parameters, sensors and adhesive was collected, and adhesion sites were settled through finite element analysis and optimization. Circuit design involved zero setting, temperature compensation, amplifying circuit, filter circuit and circuits to connect host computer. Loading calibration test was performed on sensors under static working condition. According to partial authoritative examination, the linearity was 0.06%, the repetitiveness was 0.01%, the retardation was 0.08%, and the sensitivity was 1.112 mV/V. According to the examination conducted in some metrology institute, the total work error of impact in a digital impact tester adopting the above force acquisition system was 2% of the impact value of a standard specimen, which has already reached the precision level and met the design requirement.