The aim of this work package is to consolidate the practical knowledge on AC quantum voltage standards into one document, a Good Practice Guide, to be used by laboratories who wish to construct a new apparatus for their own research programme. The Good Practice Guide will include the consolidated configuration for a general AC quantum voltage standard. The review of the different methods will include partners with expertise and partners wanting to develop capabilities on the topics to be included in the guide. The topics to be included in the guide may include the different areas of expertise:

• Josephson junction arrays designs;
• Electronic sources for low-frequency bias of Josephson junction arrays;
• Microwave sources for high-frequency bias of Josephson junction arrays;
• Construction of low-temperature (4 K) systems, both using liquid helium and cryogen-free techniques;
• Measurement methods including RMS, direct sampling and differential sampling;
• Practical techniques including operation of Josephson junctions, system configurations, cable interconnections.