Simple operation with dual test circuits, tests both wrist straps and foot grounders. Auto-ranging circuit automatically selects proper test range, user touches pad and LED displays test results. Red light and audible indicator mean circuit resistance is too high or too low. It is complied with standard 6.1.3.2 in ANSI ESD S20.20.

　　It is recommended to calibrate E0901 Checker once a year.