Difference between balanced magnetic contacts and regular door contacts

[msayewich]

Whats the difference between a balanced magnetic contact and a regular door contact? For example Flair sells a magnetic door contact and they sell a high security balanced magnetic door sensor. The price is pretty substantial and was curious what the benefits and what the flaws are. 

 

[RAL]

A balanced magnetic contact is more resistant to tampering than a regular magnetic contact, as it can sense a change in the magnetic field, rather than just the presence or absence of the magnetic field.  So if someone tries to trick the contact by placing an extra magnet near the contact, it will still trigger an alarm.

 

[msayewich]

ray: