Q: I have an application in which I want to put some sensors that would allow me to detect a person walking on a roof. I would prefer to have the sensor technology inside. I was thinking about possibly microwave detection, however there is a lot of metal and I would be concerned about false alarms as well. Any suggestions on how to protect the roof area?
A: Yes, there is a sensor technology that goes by the engineering term of a “strain gauge”. It is a device that can detect extra stress placed on a roof support beam when a person walks on the roof. The company that comes to mind is Sure Action, Inc. and the sensor system is called the Pulsor. Pay close attention to the install directions and test with a fairly light weight person as younger people can always be a burglary suspect. I think you will find a lot of applications for this sensor technology.
Q: There was a tech at work that suggested a ‘shunt switch’ for providing a local bypass for a customer’s 24 hour sensor. My only concern is that what if the customer forgets that this shunt switch is shorting out the sensor and someone breaks in. The alarm will not report. Any suggestions?
A: Yes, provide the customer with what is called a ‘supervised shunt switch’. Get a double pole, double throw control switch. Wire the switch so that when the one set of contacts shunts the door the other set of contacts creates a trouble on another supervisory loop on the alarm panel. This way the complete system cannot be armed without a notification that the shunt is still engaged.
