摘要
根据热导检测器的工作原理,分析影响其灵敏度的主要因素,并建立检测器的热平衡模型,可指导优化其性能设计。通过采用四壁直通式流通结构,选用10 kΩNTC热敏电阻作为热敏元件,设计稳定的恒流电源、高精度控温电路和信号处理电路,研制出高灵敏度的煤炭元素分析仪用热导检测器。经测试,检测器基线噪声为1.5μV,30 min内的基线漂移为8μV,灵敏度为12288 mV·mL/mg,碳元素检出限为28.4μg/g,氢元素检出限为28.8μg/g,氮元素检出限为11.3μg/g,满足高通量煤炭元素分析仪多组分联测需求。
According to the working principle of the thermal conductivity detector,the main factors affecting the sensitivity of the thermal conductivity detector are analyzed,and a thermal balance model to describe the performance of the thermal conductivity cell is established,which can guide the optimization of its performance design.By adopting a four-wall straight-through flow structure,selecting a 10 kΩNTC thermistor as the thermal element,designing a stable constant current power supply,a high-precision temperature control circuit and a signal processing circuit,developing a highly sensitive thermal conductivity detector used in the coal element analyzer.After testing,the detector baseline noise is 1.5μV,the baseline drift within 30 minutes is 8μV,the sensitivity is 12288 mV·mL/mg,and the detection limit of carbon is 28.4μg/g,the detection limit of hydrogen is 28.8μg/g,the detection limit of nitrogen is 11.3μg/g,which meets the multi-component combined measurement requirements of high-throughput coal element analyzers.
作者
胡彪
郭志明
徐开群
谭中柱
何帅
HU Biao;GUO Zhiming;XU Kaiqun;TAN Zhongzhu;HE Shuai(Hunan Institute of Metrology and Test,Changsha 410014,China;Hunan University,Changsha 410082,China;Kaiyuan Instruments,Changsha 410100,China)
出处
《中国测试》
CAS
北大核心
2022年第11期120-125,137,共7页
China Measurement & Test
基金
国家重点研发计划(2018YFF01014005)
湖南省市场监管局科技项目(2021KJJH64)。
关键词
热导检测器
灵敏度
热平衡
检出限
thermal conductivity detector
sensitivity
thermal balance
detection limit
