A voltage tester is a device used to check the flow of electrical
current through a circuit, outlet, or battery. Testers come in various
models. They are useful for making sure that equipment is working
properly. A voltage tester can also be used to check whether it is safe
to work on a circuit.
Electrical testers are a range of devices that test the presence of,
rather than measure, electrical conditions. Ranging from very simple
instruments that signal that voltage is present in a circuit, to more
complex instruments featuring multiple testing options for high-voltage
applications. Testers include tools to check voltage, batteries,
continuity, phase rotation, circuits, and more.
Taparia MDTN82 is the latest model of digital tester with much amazing features when compared with normal line tester. A comparison is shown in the video below.