4 layers

Fieldmill2
haunma/fieldmill
Hardware and software for an electrostatic field mill
112 parts1CC-BY-SA-4.0
Boards in 1 GitHub repository, designed in KiCad, that use the TLV4376IPW by Texas Instruments (-40℃~+125℃ 0.2pA 0.3pA 1uV/℃ 2.2V~5.5V 2V/us 30mA 4 5.5MHz 50uV 72dB 815uA 8nV/√Hz@1kHz ESD protection、Reverse-phase input protection Rail-to-Rail Input, Rail-to-Rail Output TSSOP-14 Precision Op Amps ROHS). See how each wires it, with its parts, size, README and files; the TLV4376IPW’s symbol, footprint and pinout are on its own page.

haunma/fieldmill
Hardware and software for an electrostatic field mill