A simple PIR sensor cannot uniquely identify a human. A PIR sensor detects long wave infrared energy. Many things generate this type of energy. All warm-blooded animals and all sources of heat generate this type of energy. A human has a characteristic temperature that is different from most other emitters and humans have a defined size range that limits the set of possible sources, so a more complex PIR sensor that can measure temperature and size may be able to distinguish a human, but it would likely require a full thermal camera and significant image processing to get any kind of accuracy.
A simple PIR sensor cannot uniquely identify a human. A PIR sensor detects long wave infrared energy. Many things generate this type of energy. All warm-blooded animals and all sources of heat generate this type of energy. A human has a characteristic temperature that is different from most other emitters and humans have a defined size range that limits the set of possible sources, so a more complex PIR sensor that can measure temperature and size may be able to distinguish a human, but it would likely require a full thermal camera and significant image processing to get any kind of accuracy.
