【作者】 韩冰；

【导师】 张钟华； 李晓苇；

【作者基本信息】 河北大学 ， 光学工程， 2004， 硕士

【摘要】 随着量子霍尔化电阻和低温电流比较仪技术的发展，我们可以建立具有不确定度为10^-9量级甚至更低的电阻标准。在比对中保持电阻环境温度的高稳定性就成为基本的要求。实际的测量活动显示可携式高精度空气控温箱可以满足这种需求，特别是在不同实验室之间的相互比对中发挥了相当大的作用。 高稳定度的空气控温箱最初是用来保存标准电池。标准电池的体积很小，所以所需的控温箱体积也不大。而标准电阻的体积比较大，同时有些高精度电阻在制作时，往往采用多段温度系数不同的电阻丝组合而成，互相弥补以达到较低的总体温度系数。显然温度的不均匀性会破坏电阻的温度特征。 本工作针对以前大容积空气控温箱内腔温度不均匀性大的缺点，采用现代控制理论的方法，设计了一种具有多传感器多加热器的新型控温箱结构。此控温箱在理论上利用矩阵正交化，对控制系统的各个部分进行解耦，使三个加热部分接近相互独立，从而使控制系统得到了较大的简化；在结构上，其内腔铝壳表面均匀绕有加热丝，内腔与控温箱外壳之间填充泡沫塑料作为绝热层，外形尺寸为50×40×46cm，内腔的尺寸为50×40×46cm，可放入一只8R102型电阻或两只Tinsley 5685型电阻。控温箱的总重量约为15千克，仍然是可以携带的。它的最突出的特性是内腔顶部与底部的温度不均匀性被自动调节，并且减少至±1mk。同时决定控温箱内腔总体温度的调节系统与在内腔顶部与底部的温度不均匀性调节系统是互相独立的。这种高精度空气控温箱在标准电阻的保存和在不同实验室之间电阻的比对将发挥重要作用。更多还原

【Abstract】 The development of QHR and CCC technique gives the possibility to establish a resistance standard with uncertainty of 10-9or less. To keep the environment temperature of the resistor to be compared in high stability becomes an essential requirement. The practical measurement activity shows that the portable air enclosure of high precision is an adequate apparatus for this purpose, which especially have a considerable effect on the case in which the inter-comparison between different laboratories.The high stability enclosure was firstly developed to maintain standard cells. The size of the standard cell is small, so the inner space size of the enclosure used to keep it is not very large too, while the size of standard resistors is much larger. Some resistors of high quality consist of several pieces with slightly different temperature coefficient and these pieces compensate each other to get very low temperature coefficient totally. Obviously the inhomogeneity of temperature will deteriorate the temperature characteristic of the resistor.In the face of the shortcoming of large capacity enclosure, which the temperature difference between bottom and top of inner space of the enclosure is large, an enclosure including multi-sensor and multi-heater is designed according to modern control theory. In theory, orthogonalization of the matrix to decouple the three parts make the control system simple and easy to run; In construction, heating wire is wound on the surface of the aluminum chamber evenly. Foam is placed between outer and aluminum chamber as thermal insulation. The outer dimension is 50?0?6cm and the inner space is 35?5?1cm, which fits one SR 102 type resistor or two Tinsley 5685 type resistors. The total weight of the enclosure is about 15 kg, which is still a portable one. Its outstanding feature is the temperature difference between top and bottom is regulatedautomatically and decreased within 1 mK. At the same time, the regulating operation determining the temperature of inner space of the enclosure and the regulating operation of the temperature difference between bottom and top is independent from each other. This enclosure is useful for the maintenance of resistance standard and for the comparison between different laboratories.更多还原