Chauvin Arnoux CA 6472 [P01126504] Earth and Ground Resistance Tester . The Chauvin Arnoux C.A 6472 earth and resistivity tester can be used for quick, comprehensive testing of all earthing systems by gathering all the earth measurement functions in a single instrument. The C.A 6472 offers the possibility of analysing the frequency behaviour of earthing systems thanks to its particularly extensive measurement frequency range from 41 to 5,078 Hz.