Sensor to identify presence of specific physical thing inside or outside of the boundary like shopping mall

Prashant_9641

Prominent
May 4, 2017
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I'm particularly looking for a sensor that can sense a specified (only defined) physical Quantity whether it's in inside or the outside of defined imaginary boundary.
 
Solution
No such beast exists. Not for a centrally located system anyways. To do what you are specifying, you'd need doorway mounted sensors running a positive-negative polarity, and the sticker would have to be designed in such a way as to take that charge and create a signature signal that would be detected. Area broadcast won't work because of signal strength loss with range, there's no guarantee the signal would remain perfect anywhere near the door. Nothing is impeccable, can't count the amount of times the cashier in Home Depot has scanned the magnet tag only for the stupid alarm to then go off as I walk out the door. I did a job in a ladies boutique on time and the alarm went off as my boss walked out. Turned out 15minutes later he was...

COLGeek

Cybernaut
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MERGED QUESTION
Question from Prashant_9641 : "Sensor to identify presence of specific physical thing inside or outside of the boundary like shopping mall"



 

USAFRet

Titan
Moderator
MERGED QUESTION
Question from Prashant_9641 : "How to sense a physical Quantity whether it's inside or outside of defined boundary."







MERGED QUESTION
Question from Prashant_9641 : "How to sense a physical Quantity whether it's inside or outside of defined boundary."







 

USAFRet

Titan
Moderator


Radar, sonar, laser...which of those technologies does not work for you?
 

Prashant_9641

Prominent
May 4, 2017
4
0
510
My project is much similar to shoplifting detection system. Im planning to attach a sticker (like shopping mall does) to shoes or other things which I perticularly want to measure within or outside of defined line.
If the leg (shoe) is out side of the line the alarm or signal should go to the computer along with impeccable precision.
 

USAFRet

Titan
Moderator


"impeccable precision" is a very imprecise requirement.
Millimeter, meter, polling frequency, number of items to be tracked...
 

Karadjgne

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Ambassador
No such beast exists. Not for a centrally located system anyways. To do what you are specifying, you'd need doorway mounted sensors running a positive-negative polarity, and the sticker would have to be designed in such a way as to take that charge and create a signature signal that would be detected. Area broadcast won't work because of signal strength loss with range, there's no guarantee the signal would remain perfect anywhere near the door. Nothing is impeccable, can't count the amount of times the cashier in Home Depot has scanned the magnet tag only for the stupid alarm to then go off as I walk out the door. I did a job in a ladies boutique on time and the alarm went off as my boss walked out. Turned out 15minutes later he was innocent of any shoplifting when the security guard finally found an old magnet strip buried in the bottom of an unused pocket of his tool case. So your special sticker would need to be totally different than any other manufacturers, would need to be physically placed by your employees in such a fashion as to not be easily removable, would have to be strong enough to bypass clothing or other obstacles like purses or bags yet weak enough not to trip the alarm when shoppers walk past the sensor while browsing.

Impeccable isn't feasible.
 
Solution