Systems and methods include an electrical switch that establishes a first electrical conducting path between terminals of an electrical measurement apparatus through one or more electrical leads and an electrically-conductive sample in a first state, and a second electrical conducting path between the terminals through the one or more electrical leads while bypassing the sample in a second state. A voltage VS+L is measured across all of the sample and the one or more electrical leads in the first state, while a voltage VL is measured across the one or more electrical leads while bypassing the sample in the second state. Calculations according to the equation VS=VS+L−VL are performed to determine a precision DC voltage measurement of a voltage across the sample VS in the absence of Seebeck voltage offsets contributed by the one or more electrical leads.