Measurement of thermal expansion at low temperatures using the strain gage method
Measurement of thermal expansion at low temperatures using the strain gage method
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DOI：
10.1631/jzus.a1400051
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发表时间：
2014-05-01
影响因子：
3.2
通讯作者：
Liu, Shu-juan
中科院分区：
文献类型：
--
作者：
Tang, Ke;Sha, Long;Liu, Shu-juan
准确的材料低温热膨胀数据对低温系统的材料选择和结构设计具有重要意义。在本研究中，建立了一个比例-积分-导数（PID）温度控制系统的实验装置，使用应变片法测量固体材料在低温（77-293 K）下的热膨胀。为了避免应变片的灵敏度系数随温度变化的影响，以确保测量的准确性，我们通过将304不锈钢的热膨胀测量数据与美国国家标准与技术研究所的源数据进行比较，对77-293 K温度范围内的灵敏度系数进行了校正。通过修正应变片的灵敏度系数，在293 ~ 80 K的冷却过程中，无氧铜的线性收缩测量值与NIST数据相当一致（相对偏差为2.37%）。
Accurate thermal expansion data of material at low temperatures are important in material selection and structural design for a cryogenic system. In this study, an experimental setup with a proportional-integral-derivative (PID) temperature control system was developed to measure the thermal expansion of solid materials at low temperatures (77-293 K), using the strain gage method. To avoid the impact of the varied sensitivity coefficient of the strain gage with the temperature to ensure an accurate measurement, we corrected the sensitivity coefficient in the temperature range of 77-293 K, by comparing the measured thermal expansion data for 304 stainless steel with the source data from the National Institute of Standards and Technology, USA. With the corrected sensitivity coefficient of the strain gage, the measured linear contractions of oxygen-free copper become quite consistent with the NIST data (with a relative deviation of 2.37%) for the cooling-down process from 293 K to 80 K.