"LoL" wrote

I have 2 and the work!
I live in FL. so it never gets to 100.
but a sensor has nothing to do with temp!!!!!!!
Try again!

You sure about that, Mr. Science???

The "motion sensing" feature on most lights (and security systems) is a
passive system that detects infrared energy. These sensors are therefore
known as PIR (passive infrared) detectors or pyroelectric sensors. In order
to make a sensor that can detect a human being, you need to make the sensor
sensitive to the temperature of a human body. Humans, having a skin
temperature of about 93 degrees F, radiate infrared energy with a wavelength
between 9 and 10 micrometers. Therefore, the sensors are typically sensitive
in the range of 8 to 12 micrometers.

The devices themselves are simple electronic components not unlike a
photosensor. The infrared light bumps electrons off a substrate, and these
electrons can be detected and amplified into a signal.

You have probably noticed that your light is sensitive to motion, but not to
a person who is standing still. That's because the electronics package
attached to the sensor is looking for a fairly rapid change in the amount of
infrared energy it is seeing. When a person walks by, the amount of infrared
energy in the field of view changes rapidly and is easily detected. You do
not want the sensor detecting slower changes, like the sidewalk cooling off
at night.

Your motion sensing light has a wide field of view because of the lens
covering the sensor. Infrared energy is a form of light, so you can focus
and bend it with plastic lenses. But it's not like there is a 2-D array of
sensors in there. There is a single (or sometimes two) sensors inside
looking for changes in infrared energy.