28 May 2017

A council depot in Dudley experiencing up to 80 false alarms in 45 minutes when opening every morning has practically eradicated the problem by reviewing the existing sensor locations and deploying OPTEX laser detection technology.

Perimeter security threat

The site requires a security system as, 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.

The site 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. However, the system suffered numerous false alarms as staff arrived for work and congregated in front of the building, and from wildlife along the canal footpath that runs along two sides of the site’s perimeter.

Rethinking detection technologies

The main cause of the false alarms was that the operational needs of the site had changed over time but the location of the existing 18 OPTEX REDWALL outdoor PIRs had not been adapted to suit. This meant that every time a staff member arrived, the alarmed sensors triggered causing a headache for operators at Visual Verification’s remote monitoring centre in Timperley, Cheshire.

Therefore, the location of the existing sensors needed a rethink as well as the mix of detection technologies specified 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 and works in conjunction with two cameras. By creating a virtual wall, the sensor only detects people standing next to the building while ignoring those further away. This resulted in the false alarm rate falling by 80%.