Electrical safety testers are instruments used to test diverse electrical safety such as testing outlet polarity, line voltage level, ampere rating, medical equipment, and others. These instruments can be used for many different types of measurements including AC or DC dielectric strength, insulation resistance, grounding systems resistance, earth continuity, AC or DC hipot, outlet polarity, line leakage, and appliance testing. Electrical safety testers may also be used for other measurement applications.