COMPARISON OF HIGH VALUE RESISTANCE STANDARDS USING THE MODIFIED WHEATSTONE BRIDGE AND PICOAMMETER

摘要

In this paper is presented the method for comparison of high value resistance standards by using the modified Wheatstone bridge and picoammeter as current detector, instead of low-impedance current-sensing transimpedance amplifier. Basically, the resistance ratio r can be measured on nominal levels 1:1, 10:1 or 100:1, ensuring the traceability chain from the reference standards of 10 MΩ and 1 GΩ for the range of interest 10 MΩ to 100 GΩ.