Proximity Tester / Hand Held Prox Tester
A proximity tester is a great tool to have in your toolbox. These prox testers are not exactly cheap but they are a must have tool for a maintenance department. Attach two or three wires and see if they work. This device also allows you to test a prox to see if it is NPN or PNP too. With proximity switches not having the best labels on them or wiring schematics this is a great quick way to determine if the prox will work for your application.