一种半导体控温装置的研制及其在电感耦合等离子体质谱仪上的应用

Development of a semiconductor temperature control device and its application in inductively coupled plasma mass spectrometer

电感耦合等离子体质谱仪具有高灵敏的元素分析能力,但也容易受多原子离子和氧化物离子的干扰。实验介绍了一种基于ARM数字控制的半导体控温装置,该装置利用高精度温度传感器和模拟数字转换器(ADC)实时采集温度,由ARM处理器实时控制半导体控温装置输出制冷量,实现了对雾室温度的闭环调节和精确控制,温度调节范围为+20^-5℃,精度为±0.1℃。通过实验表明,该系统设计可靠、稳定,对改善仪器性能指标,比如:降低氧化物的产率(以CeO/Ce为代表,该比率在加半导体制冷后降低,氧化物离子产率由10%降至6%左右)、提高信号强度和稳定性等有积极作用,可以满足质谱仪性能提升的需要。

Inductively coupled plasma mass spectrometer (ICP-MS) has high sensitivity for element analysis, but meanwhile, it is also easily affected by polyatomic ions and oxide ions. A kind of semiconductor temperature control device based on ARM digital control was introduced. This proposed device was equipped with high-precision temperature sensor and analog-digital converter (ADC) for the collection of temperature information in real time. The refrigeration output of semiconductor temperature control device was timely controlled by ARM processor, realizing the closed-loop regulation and accurate control of temperature in the spray chamber. The range of temperature regulation was +20--5 ℃, and the precision was ±0.1 ℃. The experimental results showed that the design of this system was reliable and stable, which could improve the performance of instrument, for example, to reduce the yield of oxides (represented by CeO/Ce, the yield of oxide ions was reduced from 10% to about 6% after adding semiconductor refrigeration), to improve the signal strength and stability. The developed semiconductor temperature-control device could meet the requirements for improving the performance of mass spectrometer.