On completion, the mean breakdown value of tests in the sequence is given and the value for each individual test may be recalled. Standard deviation calculations are automatically carried out and displayed when specified by the test standard. Maximum test voltage for the test set is 60 kV. The test set is microprocessor- controlled. Test sequences for many national and international standards are programmed into the test set memory.

The microprocessor controlled, semi automatic operation allows the user to select a choice of voltage rise rates as specified in many national standards. The start button will then initiate the test. If oil breakdown occurs the instrument will remove the test voltage and display the breakdown value. Alternatively the user can pause the test voltage at any time to carry out a withstand test. The voltage will be maintained at this level for one minute or until breakdown. After one minute the voltage will automatically continue to rise until breakdown occurs or to the maximum output of the instrument.