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AC-DC Transfer System for Ultra-low Frequency Voltage

This paper describes how to trace the ultra-low frequency voltage to the dc voltage standard at frequency ranges from 0.1 Hz to 10 Hz. An ultra-low frequency ac-dc transfer system is developed with using dual-heater thermal voltage converter (TVC). The dual-heater TVC can output stable thermoelectric potential when inputting two quadrature low-frequency voltages with equal amplitude. The key parameters in the ultra-low frequency ac-dc transfer system have been evaluated to make the dual-heater TVC output stable thermoelectric potential.