The tester is testing how well resistors can survive a HV (2kV) for a short moment. This is required in the TRT detector in the ATLAS experiment,where a broken wire may give a short pulse of 1.6kV through the reistors on the readout card placed on the detector itself.

Relays and capacitors are used to generate the short HV pulse. The voltage across the resistor is measured before and after the test. A CPU, an ATMEL processor (AT90S8535) , controls the test and onchip ADCs measures the voltage drop. A discharge is made repeteadly for several hours or day, with a discharge interval between 1 to 1000 seconds. Up to six resistors (R1 to R6) can be tested simultanously. A simple RS232 protocol is implemted for communication.

AT90S8535 pin configuration
(package PLCC)