Published on 28 November, 2007
Innovative external detection technology from Optex Europe, manufacturers of the award-winning Redwall range, is being deployed by South Lanarkshire Council to combat crime and reduce costly repair bills from vandalism at two primary schools in its area.
In these two schools alone, graffiti and outbreaks of fire had caused an estimated £500,000 of damage. Protecting these sites was crucial to prevent further incidents, and so Ian Porteous, CCTV Development Manager at South Lanarkshire Council looked to Optex to provide an effective solution.
"We already had CCTV installed at the schools, but it became apparent that rather than simply monitoring the vandalism, it would be more advantageous to prevent attacks before the damage was done," explains Ian. "Perimeter protection was an obvious solution to allow for early intervention, and the REDWAVE detectors came recommended to us as suitable for the purpose. We were already using another Optex product, which we knew to be reliable, and so felt comfortable in exploring further options."
"We wanted to prove that out-of-hours monitoring would be possible and effective, using the IP network, and set out to trial the detectors at the schools as a precursor to a new schools building project. Using the existing CCTV system, we have been able to add the perimeter detection devices to the premises, using video over IP to link the system to the council control centre in Hamilton, with images only monitored when a detector goes into alarm."
The Optex REDWAVE detectors, part of the Redwall family, feature the latest technology to reduce the number of false alarms. In addition to using passive infrared (PIR) and microwave technology as in conventional combination detectors, REDWAVE also has Adjustable Microwave Range Limiter (AMRL) technology that allows users to adjust the detection distance, and a Dual Quad Zone Logic (DQZL) PIR that uses two PIR detectors to increase detection density and eliminate undetectable areas.
With conventional outdoor combination detectors, microwave transmission distances are not easily adjusted, resulting in many false alarms being triggered from outside the detection area. AMRL technology incorporated within REDWAVE, however, enables installers to choose the real detection distance required with a dial setting that offers seven, five metre intervals between zero and 30 metres.
REDWAVE also uses two, vertically configured PIR detectors that create two different, highly dense detection areas, one near and one far. The dual coverage essentially eliminates dead detection spots, preventing the likelihood of ‘missed' alarms. Furthermore, the sensitivity of each area can be adjusted separately.
Each PIR uses Quad Zone Logic providing multi-segmented detection zones throughout the detection area and an alarm signal base on the cumulative energy of each zone. This greatly reduces false alarms, particularly those caused by sudden small temperature changes from light reflections or small animals.
The detectors are also linked to a tannoy system to provide voice warnings, which is also helping to slowly alter behaviour at the schools, as Ian continues: "As a well-established community school, children often come to play on the grounds outside of school hours, and others use it as a cut-through. The loud-speaker system allows us to warn the kids away from buildings or to stop them from climbing on roofs for example."
"We have already noticed that it has made a significant impact. In one case for example, a group of young people came onto the premises to smoke illegal substances. As a result of the system, we were able to alert the police and direct them to the persons even after they had left the premises. The group was followed to a local house and then arrested."
"Being able to detect intruders as they enter the premises, rather than rely on CCTV cameras to look back retrospectively at incidents has been a great help, and I am sure the findings of this trial will be useful across the entire council property portfolio. The system has done what I hoped it would, and I am certainly very pleased with it," concludes Ian.