How Does Scanning An Item Deactivates Security Sticker ?

[havelo]

When scanning an item at the check out in the supermarket does the laser deactivate the price label which has on the reverse a security printed on it ?

[Old_Geezer]

No idea but I'd suspect that was unlikely. I'd suspect electro-magnetic communication.

[Mamyalynne]

Not sure if anything here helps

http://www.explainthatstuff.com/rfid.html

[fiction-factory]

Are you talking about items such as clothing? I think special tags are removed.
For something like a multipack of tins of beans they can scan it for prices several times - sometimes if I'm buying 6 identical large items they just scan one 6 times and tell me to leave the other 5 in the trolley, so no security tag is deleted

[Jackdaw33]

I have no idea also but I will tell you of an unpleasant experience I had in Morrison's five years ago. I wasn't in the best of health but managed to traipse out and buy some shopping, amongst which was a bottle of gin. The lazy mare on the checkout neglected to remove the security cap. I didn't notice and no alarms went off when I left the store. It was only when I got home that I realised I couldn't open the bottle and have a drink. I traipsed all the way back to the store to ask them to remove it, whereupon I was treated like a criminal. They were going to call the police. Fortunately I still had the receipt proof of purchase so they reluctantly removed the security top and grudgingly gave me the bottle back. I mean, what shoplifter goes back to the shop to have the security tag removed?

[Kidas]

Mamya's right - the high value goods tend to have an RFID tag (RFID = Radio Frequency identification)

The tag is made up of two parts: the tag itself and the antenna.

The tag can store a small amount of data (up to around 1 kByte), such as the product name and product type; date of manufacture and so on.

The antenna is the square-spiral wire. This allows the transfer of data and of energy between a reader and the tag itself. It has a range of a metre or so

If the tag is not de-activated, then those gates by the entrance doors detect the tag and set off the alarms.

When you pay for the goods, the tag must be de-activated, usually by sending a specific signal through the antenna that instructs the tag to de-activate itself, so that it does not trigger the alarms by the entrance doors.

It's not done with the laser bar-code reader, but with a specific radio-frequency device. I suspect (but don't know) that the RFID de-activator is buried in the payment workstation, and the tag has to be located in a certain position when the price is scanned in. Then the RF de-activator kicks in and does its magic.

Hope it helps

[Spicerack]

The alarm at the door of my Asda seems to go off all the time. The security staff invariably wave 'the culprits' through.