低温电流比较仪动态特性的研究  

Study on the dynamic characteristic of the cryogenic current comparator

作　　者：李正坤[1] 张钟华[2] 贺青[2] 刘勇[2] 刘君华[1] 

机构地区：[1]西安交通大学电气工程学院,西安710049 [2]中国计量科学研究院,北京100013

出　　处：《仪器仪表学报》2006年第8期825-829,共5页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(60076031);国家科技部基金(2001DEA200B)资助项目

摘　　要：低温电流比较仪是现代电测量技术中最为准确的比例量具,在传递量子化霍尔电阻基准的量值时发挥了独特的作用。为了进一步提高CCC的比例准确度,一个有效的方法是采用匝数较多的绕组。但国际上各实验室均遇到了绕组匝数较高时电流会发生跳跃的困难,目前未见到对此问题进行分析及提出解决办法的文章。本文对CCC系统的动态特性进行了分析,找到了产生该现象的原因,并采取措施改进了系统的动态特性,避免了跳跃现象。与国际上的同类装置相比,CCC的绕组匝数被提高了8倍,信噪比及比例准确度也有了很大的提高。结合其他措施,完成了综合不确定度为10-10量级的量子化霍尔电阻标准装置。Cryogenic Current Comparator is the most precise apparatus for electrical measurement. To improve the measurement uncertainty of CCC further, an effective way is to increase the turn numbers of the ratio windings. But the current jumping would appear while using a CCC with large turn number of ratio windings and thus the measurement process is disturbed. There is no published paper on how to resolve the problem yet. This paper studied the dynamic characteristic of the system and found out the reason causing the troublesome current jumping. Finally, an effective method was proposed to improve the dynamic characteristic of the system and thus the current jumping was avoided successfully. The turn number ratio was increased by 8 times, and the S/N ratio was improved apparently too. With the help of other measures put forward by the authors, a Quantum Hall Resistance Standard with uncertainty of several parts in 10^-10 has been established.

关 键 词：低温电流比较仪 反馈系统 动态特性 电流跳跃 信噪比 

分 类 号：TB971[一般工业技术—计量学]