The site in Dudley, in the UK, stores building materials including paving slabs, electrical cabling and some council vehicles, and is protected by a CCTV system triggered by infrared motion detection sensors, but was suffering numerous false alarms due to staff arriving for work and congregating in front of the building, and from wildlife along the canal footpath that runs along two sides of the perimeter.

Historically, intruders have broken through one of the perimeter walls and stolen central heating boilers and piping, and also climbed up on to the roof and entered the building through the skylights.

Some 18 Redwall long range passive infrared detectors (PIRs) were installed throughout the car park and the perimeter of the building to protect the elevation of the storage warehouse a few years ago. The operational needs of the site had changed but the sensors were still in their original location and the false alarms generated when staff is arriving to work were causing a headache for operators at Visual Verification’s remote monitoring centre in Timperley, Cheshire.

The location of the existing sensors needed a rethink as well as the mix of detection technologies to specify to avoid staff triggering the system.

Replacing the traditional volumetric sensors protecting the building, a Redscan laser detector has been installed on top of the building in a vertical application, covering the facade and a one metre area from the wall, working in conjunction with two cameras. Creating a virtual wall, the laser sensor only detected people standing next to the building wall and ignored those further away. This resulted in the false alarm rate falling by 80%.

Richard Lowe, Deputy Stores and Services Manager at Dudley Metropolitan Borough Council says the depot has been targeted numerous times in the past: "It was paramount for us to get the right level of security, triggering genuine alarms the monitoring centre could act upon.”

"Thanks to the advice of the engineers at Optex, we have been able to reposition the Redwall detectors and dramatically reduce the number of false alarms experienced at the site,” says Angelo Carlesimo, Small Works Manager at Thomson AVC. "The combination of traditional PIRs and the new laser scan detector has provided the ideal solution to keep the council’s depot secure while not producing false alarms.”