Current leakage testers measure the amount of current that flows through a ground conductor. They include a measuring device or probe that connects to a conductive point, a voltmeter that displays root mean square (RMS) values, and a circuit with specific resistance and frequency characteristics. Current leakage testers are used during both normal and single-fault conditions in order to determine whether electrical devices pose a shock hazard. For medical devices and other specialized equipment, additional single-fault conditions may be required. Organizations such as the International Engineering Consortium (IEC) establish and maintain standards for acceptable levels of current leakage from different classes of devices. 

Megohmmeters

Megohmmeters generate high voltage, low current signals for testing the breakdown strength of electrical insulation. They are called megohmmeters because the insulating resistance of a properly designed product is expressed in mega ohms (M ).