A capacitive proximity sensor detects metallic objects at what relative distances compared to nonmetallic objects?

• A. Similar distances
• B. Greater distances than
• C. Shorter distances than
• D. Only at close range

Answer: (B)

Capacitive proximity sensing works by detecting changes in capacitance between the sensor’s electrode and a nearby object. A metallic object interacts with the electric field much more strongly than a nonmetallic one because metals are conductive and perturb the field to a greater extent. This larger disturbance translates into a bigger change in capacitance, which the sensor can detect from farther away. Nonmetallic materials have lower dielectric constants and weaker coupling, so they cause smaller capacitance changes and typically need to be closer to be detected. Real-world factors like object size, shape, orientation, and moisture can influence the exact range, but the general rule is that metals are detected at greater distances than nonmetals.