钢铁研究所金相室对一台1952年从瑞士进口的Dp49型光学卧式膨胀仪进行了革新改造,实现了自动化。这台Dp49型光学卧式膨胀仪大部分部件已损坏,有些已严重失灵,测一个试样需7～8小时,其结果误差很大,很难适应生产和科研的需要。针对上述问题,进行了如下几项改造: ①将落后的手动调节电阻器控温改为可控硅调功器; ②将已坏的机械程序控制改为电子程序控制; The Institute of Iron and Steel Metallurgical Room has automated and reworked a Dp49 optical horizontal dilatometer imported from Switzerland in 1952. Most of the Dp49 optical horizontal dilatometer has been damaged, some have been seriously failed, measured a sample of 7 to 8 hours, the results of the error is very large, it is difficult to adapt to production and scientific research needs. In response to the above problems, the following changes were made: ① the manual temperature control resistor behind the change to SCR power regulator; ② the bad mechanical program control to electronic program control;