| 基于应变片法的低温条件下热膨胀特征参数的测量方法与装置 |
| |
| 作者姓名： | Ke TANG Long SHA Yi-jian LI Tao JIN Shu-juan LIU |
| |
| 作者单位： | Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou 310027, China |
| |
| 摘 要： | 研究目的：为了满足低温系统的材料选择和结构设计对于材料热膨胀特征参数的需求，研发低温条件下精确、快速、方便操作、低成本的热膨胀特征参数测量方法和系统装置。创新要点：完成了卡玛合金箔应变片在77-293K低温温区敏感系数的修正，保证了基于应变片技术的低温条件材料热膨胀特征参数测量的精度；所研制装置合理的热设计和等速率式温度控制模式使得材料热膨胀特征参数在77-293K温区的测量可在14小时内快速完成。研究方法：针对77-293K温区，基于应变片测量方法，研制了采用比例-积分-微分（PID）温控系统的固体材料热膨胀特征参数测量装置（见图2和3）。通过将304不锈钢的测量数据与美国国家标准与技术研究院（NIST）公布数据进行比较，完成了卡玛合金箔应变片存77-293K低温温区的敏感系数修正（见图7和8）。采用修正后的敏感系数进行无氧铜线性收缩率测量，并与NIST公布数据比较（见图9和表2），验证了该装置在77-293K低温温区的测量精度。重要结论：获得了77-293K低温温区卡玛合金箔应变片敏感系数的修正结果；基于修正敏感系数的应变片法测量装置，采用0．3K／min的等速率式温度控制模式，可实现77-293K低温温区固体材料热膨胀特征参数的精确、快速测量。
|
| 关 键 词： | 热膨胀 线性收缩率 应变片 低温 |
Measurement of thermal expansion at low temperatures using the strain gage method |
| |
| Ke TANG,Long SHA,Yi-jian LI,Tao JIN,Shu-juan LIU.Measurement of thermal expansion at low temperatures using the strain gage method[J].Journal of Zhejiang University Science,2014,15(5):323-330. |
| |
| Authors: | Ke Tang Long Sha Yi-jian Li Tao Jin Shu-juan Liu |
| |
| Institution: | 1. Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou, 310027, China
|
| |
| Abstract: | 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. |
| |
| Keywords: | Thermal expansion Linear contraction Strain gage method Cryogenic temperature |
| 本文献已被 CNKI 维普 SpringerLink 等数据库收录！ |
