page_title: Test light
section_title: Receptacle tester
hierarchical_section_title: Test light / Receptacle tester
context_page_description: A test light, test lamp, voltage tester, or mains tester is a piece of electronic test equipment used to determine the presence of electricity in a piece of equipment under test. A test light is simpler and less costly than a measuring instrument such as a multimeter, and often suffices for checking for the presence of voltage on a conductor. Properly designed test lights include features to protect the user from accidental electric shock. Non-contact test lights can detect voltage on insulated conductors.
context_section_description: A receptacle tester (outlet tester or socket tester) plugs into an outlet, and can detect some types of wiring errors. The particular error in wiring is shown by various combinations of three lights.  Detectable errors include reversed hot/neutral, missing electrical ground or neutral, and others. However, leakage current through surge protective metal oxide varistors connected between neutral and ground of a power strip can give a false indication that a ground connection exists.
caption: North American grounded receptacle tester
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