Identification and correction of slowly decaying transients in measurements with periodic bias reversal

We describe a method to identify and correct slowly decaying transients in electrical measurements which are performed with periodic reversal of current or voltage bias. Such transients may be of different physical origin like, e.g., dielectric absorption in insulators, which often exhibit a 1/t time dependence, or the Peltier effect. We demonstrate the method with data collected in precision resistance measurements. Especially in high resistance comparisons, slowly decaying transients may lead to unnecessarily large type-B error estimates if not properly accounted for.