QUOTE(leeyung @ May 22 2012, 08:13 PM)
I think what pg84 meant is, the burglar may detached the vibration sensor from the grill. Because the vibration sensor can be easily detached without triggering the alarm.
But your point is correct also bro, I do agree witha ll of your points. so for those who intend to pasang vibration sensor over main door grill, shall put the sensor over the place where it is hard to be noticed in such away, when the burglar will be very hard to remove it

yes my fren thats what i meant .
There are few ways for a person can enter thru ur grill/door vs type of sensor that can detect.
1-use crowbar ( those really big one )to force open ,i personally have one so i know how powerful these things are - vibration sensor ( that if they did not detach the sensor first)
2-carjack ( put in between window bar and force welding point to break- happens to my house back window grill) - no sensor can sense that
3-bolt cutter ( to cut thru those thin decorative style of grill) - no sensor can sense
4-electric grinder - extreme case they pretend to be a renovation contractor. - vibration sensor
5-arc welder - extreme case they pretend to be a renovation contractor. - no sensor can detect.
these are the things in my mind when picking a alarm system and i think i still cant find a good one to deter 1-3 yet.
Of cos getting a dog ,motion sensors with lights are some deterent . But purely on prying open a grill i think its not that tough...