Verification of the low frequency ac-dc transfer difference of thermal converters using sampling with sine wave fit

Thermal converters show significant ac-dc transfer differences at low frequencies due to nonlinearities of the thermocouples. It is assumed, that the ac-dc transfer differences at low frequencies are proportional to the input power. This assumption was proofed using an independent method with sampling techniques. A novel approach based on sinewave fitting is used to calculate the effective value oft the sampled signal from the samples. It takes into account the special situation of a metrological environment.