基于半导体控温的高精密低漂移测温系统  

High Precision Low-Drift Temperature Measurement System Based on Thermoelectric Cooler

作　　者：丁炯[1] 钟银彪 俞雄飞[2] 杨遂军[1] 叶树亮[1] DING Jiong;ZHONG Yin-biao;YU Xiong-fei;YANG Sui-jun;YE Shu-liang(Institute of Industry and Trade Measurement Technique,China Jiliang University,Hangzhou 310018,China;Ningbo Entry-Exist Inspection and Quarantine Bureau Technical Center,Ningbo 315012,China)

机构地区：[1]中国计量大学工业与商贸计量技术研究所,浙江杭州310018 [2]宁波出入境检验检疫局技术中心,浙江宁波315012

出　　处：《仪表技术与传感器》2018年第9期66-70,共5页Instrument Technique and Sensor

基　　金：浙江省自然科学基金项目(LQ15F030003;LY17F010011);浙江省仪器科学与技术重中之重学科人才培育计划项目(JL150501)

摘　　要：针对绝热加速量热仪对样品微弱放热的检测需求,设计了一种基于冷端及测量电路半导体恒温控制的高精密低漂移热电偶测温系统。系统采用低噪声仪用放大器ISL28634及32位高分辨率模数转换器AD7177-2实现热电偶信号数字化采集;通过高灵敏度NTC热敏电阻进行热电偶冷端测温补偿;利用半导体制冷片针对性控制模拟电路部分温度,使其工作于恒温稳定状态,抑制电路测温漂移。实验结果表明,系统在0~450℃范围内测温精密度优于±0. 005℃,2 h内平均每min测温漂移优于±0. 000 5℃。同时,将该系统应用于绝热加速量热仪,可有效提升仪器热安全评价指标——起始反应温度检测准确度。Aiming at the weak exothermic reaction detection requirement in the accelerating rate calorimeter,a kind of high precision low-drift thermocouple temperature measurement system was proposed in this article based on cold end and measuring circuit semiconductor thermostat control.In this system,a low-noise instrumentation amplifier ISL28634 and a 32-bit high resolution analog-to-digital converter AD7177-2 were used for digitizing the thermocouple signals.The cold junction temperature of thermocouple was carried out by using a high sensitive NTC thermistor.The partial temperature of the analog circuit was controlled by means of semiconductor refrigeration chip,the temperature of the analog circuits was controlled in a constant state,thus,the temperature drift was suppressed.The experimental results show that the temperature measurement precision is better than±0.005℃and the average temperature drift per minute in 2 h is better than±0.000 5℃,in the range of 0~450℃.Meanwhile,the application of this system to adiabatic accelerometer can effectively improve the thermal safety evaluation index of the instrument,that is initial reaction temperature detection accuracy.

关 键 词：绝热加速量热仪 热电偶 高精密 低漂移 半导体制冷片 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]