BT5525 - Battery Insulation Tester (25V to 500 V)Insulation resistance test, Break down detect function (BDD), Contact check function Output voltage: 25 V to 500 V, Setting resolution 1 V Break down detect (BDD) function detects miniscule internal short circuits caused by contamination Contact check function to determine if the instrument has made proper contact with circuit under test Stable insulation resistance testing, even in noisy environments Current limit function, auto discharge function,