计量测试与工程技术
《中国测试技术》杂志社csjs

1..磁制冷材料绝热温变测试数据自动控制分析系统 郭立君,冯再,吴卫 (西华大学材料学院,四川 成都 610039) 摘要:磁制冷是目前全球公认取代氟利昂的最佳制冷方式。具有循环效率高、节能、运动部件少、无污染等优点而更富有竞争力,被誉为绿色制冷技术。评价一种磁性制冷材料的性能好坏,对其进行绝热温变测试是很重要的一步。以前采用的温变测试手段主要以人工将材料放入磁场中,手工记录为主的测试方式,其缺点失不能准确的控制试样进出磁场的速度和停留时间,造成误差较大。笔者针对这一问题,对该测试系统进行了改进,采用VB60编程,利用计算机对整个测试系统进行控制和分析并同时对数据信号进行记录分析,大大提高了测量的精度和可靠度,系统误差小于3%。本文着重阐述了笔者对绝热温变测试系统的改造方案,分析了改造后系统测试的精确度及自动化程度,并分析了误差来源及系统需进一步完善的地方。   关键词:磁制冷材料;绝热温变;控制系统   中图分类号:TK311 文献标识码:A 文章编号:1672-4984(2006)02-0008-03   Control and analysis system of the adiabatic temperature changes testing of magnetic refrigerants   GUO Li-Jun,FENG Zai,WU Wei (School of Materials Science and Engineering,Xihua University,Chengdu 610039,China)   Abstract: The magnetic cooling is regard as the best way taking place the traditional cooling method,which has many advantages such as high efficiency, energy conservation, uncomplicated and pollution free. Adiabatic temperature changes testing is one of the most important way to evaluate the coo ling ability of the material. The unimproved testing device and method is based on the manual work, the error is inevitable. So we reconstructed a testing device and design a the control and analysis program based on Visual Basic 6.0,this system greatly improved the accuracy and reliability of the test, the error less than 3%. This article is highlights to expatiate the whole developing process of this system and analyze the accuracy of the result and automatization degree of the system. In the last part, we analysis the disadvantage of the system and the sources of errors.   Key words: Magnetic refrigeration materials; Adiabatic temperature changes; Control system