SUBTERRANEAN PRESSURE DETECTION
Two tubes are installed underground to set up a discrete detection sensor. The tubes are installed approximately 25cm deep with a gap of 1.5m between them.
The system is based on the detection of pressure signals created by an intruder crossing the sensitive zone. The tubes are filled with a liquid that allows the system to operate at very low temperatures (anti-freeze), and then pressurised. A crossing of the sensitive area creates a difference in pressure between the tubes that is detected and processed by a transducer.
As with many systems, the received signals are processed and appropriate alarm signals are annunciated. Known signals, such as roads and railways can be rejected, which makes the system suitable for sites subject to high levels of environmental interference. The system is also immune to atmospheric conditions such as hail, rain or snow.
This system is available in a “Point ID” version. Various companies are developing “point ID”, which is a process of identifying the point at which a detection system is activated. The system can detect a crossing within plus or minus 5m, giving a maximum of 20 crossing points within a 200m protected zone.
Subterranean detection can be installed on either side of a physical barrier or in open space. It can be buried in a variety of materials, including asphalt, block paving, gravel and lawn. These systems are ideally suited for areas that need covert detection such as lawns and open spaces or areas that cannot have their aesthetics disturbed. This form of detection can follow irregular ground profiles both horizontally and vertically.