But based on the incomplete statistic , the amount of universal testing machine with electro - hydraulic servo controlled that can be used normally is no more than half since it is manufactured in 1987 . so the analysis and study on the typical test machine - the pws - 100 dymamic & static universal test machine with electro - hydraulic servo controlled is presented 然而据不完全统计,国内市场伺服阀式试验机自1987年开始生产至今,能正常使用的不足一半,因此,本次研究选择该试验机中的典型机pws - 100型电液伺服动静万能试验机进行分析计算。