Number 4 –> What are capacitive proximity sensors?
A basic proximity sensor is used to sense the presence of objects or materials. What differentiates them from other sensors is that they don’t make physical contact with the object being sensed, and hence they’re also known as non-contact sensors. One of the most common sensor types is the capacitive proximity sensor. As the name suggests, capacitive proximity sensors operate by noting a change in the capacitance read by the sensor.