小电流测量单元校准技术研究

Research on Calibration of Low Current Measurement Unit

在电子、航空航天领域及型号工程中小电流测试设备(如静电计、皮安表、源/测量单元、半导体精密分析仪等),发挥着极其重要的作用,其电流测量分辨力达到fA级,接近其物理极限值。对这些高灵敏度、高分辨力的精密小电流测量仪器进行参数校准是一项新的计量难题。本文使用Fluke公司5440B型直流电压源和自行研制的高值电阻器,构成测试平台,可以对Keithley公司6517B型静电计(20pA～2μA电流量程)进行自动校准。软件采用Visual C++6.0利用校准算法对测量结果进行分析,解决了小电流测量单元校准的计量难题。

Low-current test instruments （such as the electrometer, Pico ammeters, source/measure units, semiconductor precision analyzers, etc. ） play an extremely important role in the electronic and aerospace field and model engineering. The current measurement resolution level of fA grade touched its physical limit. It is a new metrology challenge that the precision low current measurement instruments of high sensitivity and strong resolution are calibrated. Fluke Instrument＇s 5440B and self-developed NIM- TΩ was used to constitute test platform in this article to calibrate Keithley Instrument＇s 6517B （current range： 20pA- 2μ A）. Visual C ＋ ＋ 6.0 was used to develop calibrating software through analysis of measurement results. The metrology difficult problem of low current measurement unit calibration was solved.