Chauvin Arnoux CA 6422 [P01127012] Earth Ground Meter. The Chauvin Arnoux CA 6422 earth tester is ideal for intensive use in the field. This tester can be used for 2P and 3P earth measurements. The connections are clearly identified with text markings and colour coding. All the measurements and functions are directly accessible on the instrument's front panel, even when you are wearing gloves. The CA 6422 is equipped with a backlit LCD screen which is particularly easy to read. A LED indicates when a hazardous voltage is present, while the NOISE symbol flashes to indicate when a noise voltage is present.