多通道1 mK精密测温仪设计与实现

Design and Implementation of Multi-Channel 1 mK Precision Thermometer

随着科学技术的不断进步,测量系统对测温的准确度和稳定性等性能提出了更高的要求。在航天、航空、海洋、气象、农业、生物等行业中,温度是常见的基本物理量,很难直接测量。提出了一个基于精密铂电阻温度传感器的测量精度高、测量稳定性好、成本低的温度测量方案。该方案易于扩展,满足多路测温产品的需求。通过高带载能力双向恒流源设计、多通道技术实现、测量方法的改进、测量方式的转换、精密信号处理以及零功率功能等关键测量技术的实现与突破,完成了多通道精密测温仪系统设计。试验结果表明,系统可实现36路温度测量,并具备72路温度测量能力。测试数据表明,该系统实现了优于1 mK的温度测量不确定度。

With the continuous development of science and technology,the stricter requirements are put forward for temperature measurement system on the accuracy and stability especially in the fields of aerospace,aviation,oceanography,meteorology,agriculture,biology,etc.Temperature is the common fundamental physical quantity.Furthermore,it is a physical quantity which is the most difficult to measure directly.A scheme based on precise platinum resistor with high measuring precision,good stability and low cost is accomplished.Meanwhile,this scheme is easily expanded to satisfy the demand of multi-channel thermometry.Thus,multi-channel precise temperature measuring system is fulfilled through following key techniques such as high load capacity bi-directional constant current source,multi-channel technology,improvement of measuring method and transformation of measurement mode,precise signal processing and the realization of zero power function.The experimental results show that 36-channel temperature measurement is realized.Furthermore,the capacity of 72-channel thermometry can be expected.The test data indicates that the temperature measuring uncertainty of better than 1 mK is realized by this system.