Good practice guide on the graphene-based AC-QHE realization of the farad

This guide provides information for the realization of the farad from the quantum Hall resistance in graphene devices by using digital impedance bridges. This guide provides a detailed description of how to set up a laboratory to perform measurements of artifact capacitance standards in terms of the quantized Hall resistance in graphene devices. The fabrication and characterization of graphene quantum Hall effect devices, the cryogenic environment required to achieve the quantization conditions, the digital impedance bridges and calibration procedures are reported.