Electronic test equipment, measuring apparatus and diagnostic equipment, namely, voltage testers for electrical installations, especially medium and high voltage installations; electronic test equipment, measuring apparatus and diagnostic equipment, namely, voltage testers for power engineering equipment; protective relay test equipment, namely, overvoltage protection relays; electronic protective test equipment, namely, voltage testers; current transformer test equipment, namely, pulse generators for testing electric current; instrument transformer test equipment, namely, electric sensors; power transformer test equipment, namely, electric sensors; circuit breaker test equipment, namely, electric sensors; rotating machinery test equipment, namely, electric sensors; grounding system test equipment, namely, electric sensors; medium voltage and high voltage line test equipment, namely, voltage testers; partial discharge electric meters; partial discharge analysis systems comprising electric meters; reclosure control test equipment, namely, voltage testers; high voltage equipment insulation test equipment, namely, voltage testers; dissipation factor meters, namely, electric meters; sweep frequency response SFR analyzers, namely, frequency meters; precision time protocol PTP time frequency converters