How does a Capacitive Proximity Sensor detect targets?

A Capacitive Proximity Sensor operates on the principle of detecting changes in capacitance when an object comes within its sensing range. These sensors create an electrostatic field around the sensing area, and when a target, which can be either conductive or non-conductive, enters this field, it alters the capacitance between the sensor and the object. This change in capacitance is then detected by the sensor circuitry, triggering a response.

The sensor does not need to make physical contact with the target; it can sense multiple materials, making it versatile for different applications. The capacity variations are translated into an output signal, allowing for accurate detection without requiring a direct line of sight or any physical measurement of the target's distance.

The other methods outlined do not match the operation of a capacitive sensor. For instance, magnetic fields and light reflection pertain to other types of proximity sensors, such as inductive sensors (which measure magnetic fields) and photoelectric sensors (which work with light), respectively. Similarly, the use of ultrasonic waves refers to ultrasonic sensors that measure distance based on the time taken for sound waves to return. Thus, option C accurately describes the functional principle of a capacitive proximity sensor.