A
Yes, it changes. The output of the sensitivity of a pyroelectric infrared sensor changes
due to the temperature difference between the background temperature and the object (people). For this
reason, as the temperature difference becomes lower the change in the output also becomes lower in
principle, and the detection range becomes shorter as a result.
There is no output of sensitivity
when the background temperature is equivalent to the body temperature in principle. Since the surface
temperature of a human body is uneven, the detector will never completely stop detecting in practical
use.