Why are those shoptlifting magnet detectors so short? Why don't they resemble airport metal dectectors?

Question

Do people steal stuff from stores by throwing items over them ?

Answer 1

The anti-theft devices are specifically designed to be detected by the sensor, while the airport detectors must be versatile enough to detect all sorts of shapes and sizes. A good analogy would be a missile hitting a target with a built-in beacon *designed* to inform the missile of its location, vs an "uncooperative" target that dodges.

Answer 2

They are RFID sensors. Each sensor has a coil in it which powers a chip and a low power transmitter. When the coil on the shop item passes through the big coil at th door (which is radiating a field and detecting a valid code from the chip in the item being stolen. This works because it induces a current in the little sensor which powers the chip/transmiter.

If the item has not been 'disabled' at the checkout, an alarm sounds. You can see the checkout prople actually swiping them to disable the code and show it has been bought legitimately.

There is one way at least (that I know of) around then.

The detectors come in dozens of shapes and sizes, Some can be inserted through a hypodermic needle, most are very flat, others are the shape of keyrings - in other words, you simply cannot tell what an RFID transducer looks like. They are used in pet ID tags). The smallest are tiny (but the smaller the are, the less their range.

RFID stands for radio frequency ID.

RFID has a MUCH bigger maket in tracking shipments internationally and will slash freight costs one day. Catching shoplifters is a tiny afterthought of an application, or tracking items on a production line.

Answer 3

The chip is Activated,it has to be de-activated to pass through the detectors.use a magnet to de-activate it.

Answer 4

because they are not metal detectors