how do motion sensors detect movement?

Question

if you can't be detected behind glass, can't burglars carry a glass shield in front of them and avoid detection?

Answer 1

It really depends on the motion sensor. There are two types, active and passive. Active sensors include the sensors that open grocery store doors (these send out microwave radio energy then wait for it to bounce back), also alarms that emit beams of light (if the beam is broken the change in light is detected). Active sensors basically send something out into the environment and receive the changes. The motion sensor in most alarm systems are considered passive dectectors because they don't emit anything, but detect changes in energy such as infrared energy. These are usually set to detect small changes in the temperature of the human body. One cool experiment is if you stand behind a window, the motion sensors won't "see" you! This is because glass isn't a good conductor of infrared energy. Either way, these devices are interesting inventions!

Answer 2

alot of issues might reason dizziness my first concern may well be to have your blood tension checked, if its too intense or very low you are able to replace into dizzy, additionally a sinus an infection, or an ear an infection, might reason dizziness, I even have meineres ailment that's a ailment of the interior ear and it makes me so dizzy that i'm getting unwell, it may take place to all and sundry and there's no rationalization why one guy or woman gets it and yet another would not. If it maintains i might see a physician to rule out a style of or something that would desire to be happening bodily with you.

Answer 3

There are many kinds of detectors. See the link.

Answer 4

The same way I can spot a queer dood a mile away....oop - wait a minute no that's gay-dar.

Answer 5

Why they are called motion sensors if they don't?

Answer 6

ifrared like remotes

Answer 7

don't know