When using a multimeter, what readings confirm the proper function of a proximity sensor?

Confirming the proper function of a proximity sensor using a multimeter depends on the sensor type and its wiring configuration. A proximity sensor detects the presence of an object without physical contact. Common types include inductive, capacitive, and photoelectric sensors. Inductive sensors detect metallic objects, capacitive sensors detect both metallic and non-metallic objects, and photoelectric sensors use a beam of light. The multimeter readings will vary based on whether the sensor is a two-wire, three-wire, or four-wire type. For a two-wire sensor, ....