多通道温度测量整体校准系统仿真分析

Simulation and Analysis of The Whole Calibration System for Multi-channel Temperature Measurement

为了实现低温风洞等设备高精度温度场测量目的,需要综合考虑温度传感器、连接电缆、调理放大器、数据采集系统以及环境等各种因素产生的综合误差,设计一套在低温范围内对温度测量系统进行整体全回路原位校准装置;针对整体全回路原位校准装置在准度、温度场均匀性、温度场稳定性等各方面的高精度要求,在装置方案设计完成后,对其核心部分隔热校准腔进行了热力学仿真计算,对其主体三层结构型式、绝热技术、引线密封方式、温度场均匀性保证措施等进行了模拟计算,并建立了实验平台对仿真结果进行了实际验证和方案优化;仿真和实验验证结果证明,低温温度测量系统整体校准装置所采用的设计方案能够满足一次校准通道数11路和在77~323 K温度范围内温度准度50 mK、有效温度场均匀性50 mK等技术指标要求。

In order to achieve the purpose of high-precision temperature field measurement,it is necessary to consider the comprehensive error caused by temperature sensor,connecting cable,conditioning amplifier,data acquisition system and environment,and design a set of whole loop in-situ calibration device for the temperature measurement system in the low temperature range.In this paper,the thermodynamic simulation calculation of the thermal insulation calibration chamber,which is the core part of the whole calibration device,is carried out.The three-layer structure of the main body,insulation technology,lead sealing mode,temperature field uniformity assurance measures are simulated and calculated.The test platform is established to verify the simulation results.The simulation and experimental results show that the design scheme of the whole calibration device of the cryogenic temperature measurement system can meet the requirements of 11 channels in one calibration,temperature accuracy of 50 mk and effective temperature field uniformity of 50mk in the temperature range of 77 K to 323 K.