AEMC 6422 [2135.55] 3-Point Digital Ground Resistance Tester. The Digital Ground Resistance Tester Model 6422 performs resistance and 3-pole ground resistance measurements. This direct reading tester is auto-ranging, so it automatically seeks out the optimum measurement range. The Model 6422 is easy to use - simply connect the leads, press to measure, and read. The large LCD also indicates low battery status and overrange. Model 6422 comes with 3 safety color-coded terminals to aid in easy hookup and it is powered by 6 x AA alkaline batteries. The Ground Resistance Tester Model 6422 is also available in a complete Kit (150ft).