液氮低温环境下电阻应变片测试性能的试验研究

EXPERIMENT STUDY ON MECHANICAL PROPERTIES BASED ON RESISTANCE STRAIN GAUGE UNDER LIQUID NITROGEN COOLING ENVIRONMENT

分别采用低温电阻应变片及拉线式位移传感器的电测技术,该文开展了液氮浸泡下的悬臂梁结构在静载条件下的应变测量。对两种实验测试结果和理论分析结果进行了对比和精度分析,给出了相应的实验标定曲线,并探讨了测量过程中应变片粘接、电桥连接方式、液氮冷却和数据采集对实验结果精度的影响因素等。结果表明:在采用温度补偿和应变片的正确粘贴和良好固化情形下,低温应变片能够在液氮低温区给出较高精度的应变测量;拉线式位移传感器几乎不受低温的影响,测量简单易行。相关技术和结果将为中科院近代物理研究所自主研制的兰州潘宁离子阱7T超导磁体的低温下应变测量提供方法和指导。

Based on a low-temperature strain gauge and an extension displacement transducer, this paper presents the strain measurement of a cantilevered beam soaked to liquid nitrogen. The accuracy of the measurements was compared, and the corresponding calibration curves were obtained. Some factors including the strain gauge bonding, bridge connections, liquid nitrogen cooling and data acquisition influenced on the experimental results were discussed. The results show that low-temperature strain gauges can work well in liquid nitrogen cooling environment when the proper experimental conditions are considered such as temperature compensation, firm paste and good curing. The displacement transducer is little affected by low temperature environment, and it was convenient to measure the displacement of a structure under liquid nitrogen cooling environment. The present results may provide some basis measurements on mechanical properties of Lan Zhou Penning ion Traps 7T superconducting magnet developed at the Institute of Modem Physics, Chinese Academy of Sciences （IMP, CAS） in low temperature environment.