IR motion sensor to calculate number of people in a given space

Hello,

I am trying to find the right sensor or combination of sensors to calculate the number of people in a given space.

Would it be possible to use a motion sensor or is that to limited to just motion, regardless the number of people?

I appreciate any ideas on sensors to accomplish that.

Thanks, Flea

This is a very difficult task -- not something a motion sensor and Arduino can accomplish. A camera and PC could work, in certain circumstances.

General IR sensor

The problem with using a generic IR to count people is that the sensor physics were designed to determine hot-body motion. So, said another way, the sensor activates when something “warmer than ambient” moves in its field of vision.

The sensor does not know if the motion is a human or a horse.

This Wiki article explains how the work

Good luck,

Ray