Features:Microprocessor-controlledAutomatic voltmeter AC/DC at Start/ResetAuto rangeAuto offBattery testBattery test at switch ON/ResetSafety voltmeter before each testAuto discharge on all test and all rangesLeads Auto-Null keyTest Auto-StopSmart hold and stop on voltmeter ac/dcEner-Save feature to extend battery lifeContinuity short circuit current > 220mAContinuity open circuit voltage of 5VdcNominal voltage at 1 mA on all insulation rangesAccept 8 rechargeable batteries or Alkaline or normalBS 16th editionDAR (Dielectric Absorption Ratio). The dielectric Absorption Ratio is the ratio of the Insulation Resistance measured at 1 min divided per the Insulation Resistance measured at 30 seconds. 30 seconds after starting a test (with EnerSave disabled), the tester will beep, indicating the operator that the resistance value measured at 30 second now has been saved internally. 1 minute after starting a test (with EnerSave disabled), the tester will beep again, indicating the user that the DAR result is now computed and change the display format to now display the DAR result.PI (Polarization Index). The Polarization Index or PI is the ratio of the Insulation Resistance measured at 10 minutes divided per the Insulation Resistance measured at 1 minute. 10 minutes after starting a test (with EnerSave disabled), the tester will beep again, indicating the user that the PI result is now computed and change the display format to now display the PI result. The tester will Auto-Stop at 10 minutes.Voltmeter. When testing insulation resistance while there is a presence of voltage (whether ACV or DCV) on the measured object, conventional insulation testers are highly susceptible to damage. With this new line of insulation testers, it has the ability to switch to voltage detection mode without damaging the once it detects the presence of voltage. It will also display the voltage finding on the LCD screen. With this new and unique function, it will allow the user to safely rule out the possibility of any presence of voltage on the measured object prior to measuring its insulation.