Keithley 2461

Section
4: Source-measure considerations Model 2461 Interactive SourceMeter® Instrument
Reference Manual
4-20 2461-901-01 A/November 2015
Voltage measure accuracy:
Input signal = (20 Ω x 100 mA) = 2 V
Accuracy specification of 2 V range = ± (0.012 % of output + 300 µV)
= ± {(2 V x 0.00012) + 300 µV}
= ± {240 µV + 300 µV}
= ± 540 µV
Error %
=± 0.027 %
Total measurement uncertainty = 0.035 % + 0.027 % = 0.062 %
For higher accuracy measurements when using SMU Instruments, use the source readback function
to actually measure the source output. Use the measured source value to calculate the resistance.
To calculate the total accuracy from this example using source readback, add the current and voltage
measurement accuracy specifications.
Current measure accuracy:
Input signal = 100 mA on 100 mA range