Vanguard's Model VBT-60 is a microprocessor-based, portable 60 kV dc Vacuum Bottle Tester. This tester is light-weight, portable, and designed for testing circuit-breaker vacuum bottles in the field and at the shop.

The VBT-60 permits users to select test voltages from a range from 10 kV dc to 60 kV dc in 5 kV steps. Once the test voltage reaches its preset level, a dwell timer holds this voltage at that level for the preset time duration. After the dwell time has elapsed, the test voltage returns to zero. The high-voltage test dwell time can be set from 5 seconds to 2 minutes. A flashover condition (i.e., a bottle failure) is indicated by a "Failure" indicator on the front panel.