Put Electrical Tests on Automatic
The 7 Series testers are designed for safe, automatic measurements of ac volts, dc volts, resistance and continuity. Simply turn on and use. 

Auto Selection simplifies voltage measurements in power environments. When measuring ohms/continuity with more than 4.5 volts present across the input jacks (intentional or not) the meter automatically switches to measuring ac or dc volts, whichever is greater. Input impedance is approximately 2kOhms, helping determine if voltage is from leakage (so-called "ghost" voltages) or a hard connection. Overload protection is provided in all measurement modes.