A dual-element pyroelectric sensor generates which of the following?

A dual-element pyroelectric sensor is specifically designed to detect changes in infrared radiation, which is commonly associated with the movement of warm bodies, such as human beings. When such movement occurs, the sensor detects variations in the infrared energy that is emitted or reflected from the object.

The key feature of a dual-element sensor is that it consists of two elements that allow it to respond to the differential heat changes. When an object approaches the sensor, one element may experience a rise in temperature while the other may not experience the same change immediately. This temperature difference generates a positive signal from the element that detects the increased infrared radiation and a negative signal from the other element which is not experiencing the same change. As a result, the sensor produces both a positive and a negative signal pulse, which effectively indicates the detection of movement.

This dual-output capability enhances the sensor's ability to accurately identify motion and helps in minimizing false alarms by providing a clearer indication of changes in the environment. Therefore, the generation of both positive and negative signal pulses reflects the operational principle of the dual-element pyroelectric sensor effectively.