The Model 4048la a combination Electro-Static-Discharge (ESD) tester and AC Dielectric Withstand (Hypot®) tester, referred to as Model 4048 ESD/ HYPOT® Tester. It serves as a field maintenance tool, as well as an R arid D tool. Its ESD capabilities for evaluating electronic equipment, particularly computer equipment,for susceptibility to static electricity.As an AC HYPOT, dielectric withstand (overvoltage) tests can be performed to check, integrity of the electrical insulation system.