Product Technology

ENCLOSURE - Volumetric Series

The ENCLOSURE product line is an outdoor electronic perimeter intrusion detection system. The Volumetric series sensors are based on ported (leaky) coaxial technology. An invisible electromagnetic detection field of 2m (6ft) wide, i.e.: 1m (3ft) radius, surrounds the leaky coaxial cable to detect the presence of a moving object, such as human intruder; small animals and flying debris do not generate false alarms. Every zone length is available from 5 to 50 meters (16 to 165 feet) maximum of volumetric perimeter protection. Each processor is capable of 2, 4, or 8 individual detection zones. In addition, this technology is 100% immune, and therefore not affected by, wind, fog and sunlight weather conditions. The coaxial cable can be buried up to 20cm (8 inches), mounted on a concrete wall or rooftop, and even laid-down on the ground surface following the secured contour. Indeed the sensor cable can be mounted on any non-metallic surface. For metallic surfaces, PVC or non-metallic standoffs are used to raise the coaxial cable to a minimum of 20cm (8inches) above the metal surface.

There are several possible configurations available for each application which varies depending on the environment. The product line includes several systems in fix and portable versions with a different number a maximum zones. These systems protect perimeters with good resolution and properly integrate video assessment using volumetric technology.

Active Mode Leaky Coaxial Systems: In the active mode, a series of “active” transmitters are placed to set-up a detection field. Likewise in cellular phone industry, each transmitter operates on a unique set of frequencies forming a detection field frequency tag. The common receiver scans a multiple set of frequencies (that the transmitters are sending) and identifies the zone being intruded by differentiating the frequencies, since each zone has a unique set of frequencies. The number of transmitters per receiver could be 2, 4 or 8 based on the model used. For reliability reasons each transmitter generates two frequencies. Frequencies for both transmitter and receiver are manufactured factory preset and can be modified on site if necessary. The RF signal strength generated by the transmitting sensor cable is very low and therefore license free in most countries. Consult Auratek for further information on licensing.

Passive Mode Leaky Coaxial System: In the passive mode, the nearby commercial FM broadcast transmitters act like a “transmitter of opportunity”. Since this system has no control on the stability of these commercial RF signals, the receiver operates on a total of 8 frequencies per zone, with a maximum of 2 zones per receiver. This passive mode system is restricted to operate in an urban area and it must be located within a maximum distance of 16 Km (10 miles) from a 100 KWatt commercial FM antenna tower. This type of installation is more site specific and demands the supervision of a qualified radio engineer.

Frequency Bands of Operation: The ideal frequency to detect human size intruders and to reject small animal is within the VHF band. Therefore, in order to minimize any risk of mutual interferences between the broadcast RF signals and Auratek security systems, the active systems operate within the TV band, more precisely between the audio and the video carrier frequency of TV channels. For North, Central, South America and most Asian countries the TV band of operations are TV channel 4, 5 and 6 referred to as TV band. For European countries the TV band of operations are L2, L3 and L4 referred to as TVe band. For other countries that do not fall under TV and TVe bands it is recommended to operate in the FM band. Note that for obvious reasons, the passive system is restricted to the FM band. The frequency bands of operation must be specified in the order form during purchase and affect only the Transmitter and Receiver modules. All accessories, including sensor cables are identical for all 3 frequency bands, except for dipole antennas when used.

ENCLOSURE - Acoustic Series

The Acoustic series sensors are based on microphonic technologies. A linearly distributed arrays of microphones formed by the acoustic cable detects the presence of an intruder by processing the acoustic noise induced by the intrusion. The acoustic cable is “acoustically” coupled to the physical barrier forming the secured area. Pressure, noise and vibration induced to such barrier will generate an intrusion alarm. Typically, such barriers consist of chain-link and palisade fences but can also be installed on a wooden fence and under a cap of a cement wall. In some restricted applications, the acoustic cable could be located in a gravel bed detecting the pressure/vibration induced by a walking intruder. Acoustic microphones are offered in two different technologies: fiber optic and coaxial sensor. There are some techniques to cross gates and to have a non-detection section within a zone. Each processor offers one zone of detection.

Fiber Optic Sensor Cable Systems: The fiber optic acoustic system detects the vibration/noise/pressure induced to the light-carrier signal that propagates inside the fiber optic cable. Due to natural immunity against EMI and electrical discharged (i.e.: lightning), the optical fiber system is ideal for high potential EMI and high voltage site. Since the fiber optic acoustic system offers very long zone capability, the transceiver is limited to only one zone per system. A version of the system allows the use of non-sensitive fiber to physically separate the transceiver from the zone. With the fiber optical system, the sensor cable needs to form a complete loop, which is typically achieved by placing the output run on the top of the fence with the returned run on the bottom of the fence.

Coaxial Sensor Cable Systems: The coaxial acoustic system detects the vibration/noise/pressure capacity induced to the electrical carrier signal that propagates inside the coaxial cable. Due to the resistive natural, coaxial system presents shorter zone than optical fiber system. Since the coaxial acoustic system, offer shorter zone, each receiver system offers one or two zone processors. These systems also allow the use of non-sensitive coax to physically separate the receiver from the zone. The coaxial sensor cable zone can easily be terminated with an end of line termination load without the need to complete a loop.