electronic testing equipment and measuring equipment, namely, differential amplifiers, calibration generators, function generators, pulse generators, time mark generators, sine wave generators, signal generators, counters, power supplies, audio test systems comprised of a programmable oscillator, programmable distortion analyzer, a controller, and optical frequency counters, signal switchers, interface devices, disc storage, and hard copy plotters, for performing and recording test results of critical audio measurements, programmable scanners, power module mainframes comprised of a common power source that allows combining different electronic test instruments to configure different multifunction and application specific packages for manual and automatic electronic testing, resistors, potentiometers, decade ratio transformers, resistance transfer standards for calibrating various resistance values of other metrology and calibration lab equipment, resistance standards for calibrating a single resistance value of other metrology and calibration lab equipment, ohmmeters, comparators, resistance measuring systems comprised of in-line decade resistors, coaxial-dial decade resistors, ratio transformers, resistance transfer standards, digital ohmmeters, and portable impedance bridges, for performing and recording critical resistance, capacitance and inductance measurements, impedance measuring systems comprised of digital impedance meters and AC ratio transformer standards, for evaluating and inspecting electronic components, transformer standards for calibrating various resistance values of other metrology and calibration lab equipment, voltmeters, resolver bridges, resolver standards for introducing known inputs for testing auto pilots and aircraft indicators, voltage calibrators, temperature calibrators switchboxes, thermometers, voltmeters, phase testers, solder system testers, temperature probes, line impedance stabilization networks, current probes, calibration fixtures, and directional couplers