Physical Sciences and Mathematics Commons^™

Using Ohm's Law To Calibrate A Picoammeter To 0.4 Pico-Ampere Precision, Joseph Hashem, Tiankuan Liu, Zhihua Liang, Jingbo Ye

Journal of Undergraduate Research

We present an experimental method based on Ohm’s Law to calibrate the Keithley 6485 picoammeter with the calibration error less than 0.4 pico-ampere (pA), which is specified as the highest sensitivity of this instrument. The maximum calibration difference between the measurement current and the calibration current in the picoammeter’s 2 nano-ampere (nA) range is 0.25 pA. This difference is far less than the highest accuracy, 0.4 pA, specified by the instrument. Measurement errors are estimated and discussed.