Electrical measuring instruments, namely, instruments for determining the voltage at which electrical insulation breaks down, instruments for measuring the resistance of electrical grounding connection to the earth, instruments for measuring the electrical resistance of electrical insulation, instruments for measuring the leakage current present in electrical insulation and replacement parts therefor, electrical safety compliance analyzers for use by the producers of electrical products for testing for compliance with industry standards for AC hipot, DC hipot, forty amp ground bond, sixty amp ground bond, insulation resistance, and functional run or line leakage, and for testing manufactured electric products, namely, computers, lighting fixtures, lighting ballasts, appliances, medical devices, motors, printed circuit boards (PCBs) and components of PCB's, and instruments for determining the voltage at which electrical insulation breaks down, instruments for measuring the resistance of electrical grounding connection to the earth, instruments for measuring the electrical resistance of electrical insulation, instruments for measuring the leakage current present in electrical insulation, and electrical and electronic measuring and testing devices provided with user adjustable settings for powering up for use in measuring and testing electrical power fluctuations; electrical and electronic instruments for measuring and testing the performance, strength and efficiency of electronic and/or electrical products; electrical circuits used to monitor current leakage from electrical safety testing devices to the ground sold as a component part of the electrical safety testing devices; electrical measuring instruments used for testing the safety ground circuit of consumer and industrial products; electrical instruments used to test commercial products on a variety of electrical safety specifications including tests for AC hipot, DC hipot, insulation resistance, ground bond, functional run and line electricity leakage test, electrical instruments used to perform electricity leakage tests on commercial products, electrical instruments used to apply preselected electrical power loads to simulate possible power loads when using the products being tested, and electrical instruments used to simulate fault conditions while tests are in process; electrical instruments used to test commercial products on a variety of electrical safety specifications including tests for AC hipot, DC hipot, insulation resistance, ground bond, functional run and line electricity leakage test, electrical instruments used to perform electricity leakage tests on commercial products, electrical instruments used to apply preselected electrical power loads to simulate possible power loads when using the products being tested, and electrical instruments used to simulate fault conditions while tests are in process; electronic testers used in testing medical equipment; and replacement parts therefor