Intrusion detection by means of motion detectors is particularly difficult in schools and Kindergartens, as they are often characterised by many things hanging in windows or from ceilings, such as curtains, drawings or children’s handicrafts. Being located in the northern parts of Sweden with winter temperatures frequently going down below minus 20 or even minus 30°C, Umeå Kindergartens do often have to run their heaters on full power. This creates a lot of draft which tends to move loose hanging items and thus easily creates false alarms. As a result, the Kindergartens had an average of five false alarms per year each.

When Umeå Municipality’s technical department came across Bosch and the Professional Series Intrusion Detectors during a trade show in Stockholm, they immediately decided to do some real life testing. The Professional Series Intrusion Detectors have rigorously been designed with false alarm immunity in mind and is based on a blend of technologies that help to achieve this goal.

Anders Forsberg, a technical engineer who works with security and energy conservation at Umeå Municipality, evaluated both a PIR detector and a Tritech plus detector with anti-mask technology and was impressed by their behaviour: “We made tests with horizontal and vertical movements, with flickering paper, even with direct light from a strong source”, Mr. Forsberg reports. “In all situations, the detectors behaved as we would have liked them to behave, offering one hundred percent detection rate while minimizing the number of false alarms.” The detectors also proved sensitive enough to be used as presence detectors for light control in the kindergar-tens in addition to intrusion detection purposes.

In early 2009, Umeå Municipality installed Professional Series Intrusion Detectors in all three Kindergartens and the school and has since dramatically reduced false alarms to a minimum level. Compared to five false alarms per year each, this saves a lot of money. Anders Forsberg comments: “Return on investment was very fast, and now we continue saving money that can be better used for education purposes.”

The Professional Series Intrusion Detectors from Bosch are a comprehen-sive family of motion detectors that implement a variety of innovative technologies to ensure a cost-effective, failsafe installation. These technologies include trifocus optics with three lenses and sensor data fusion (SDF) digital signal processing which correlates signals from up to eight sensors to achieve highest levels of accuracy. The combination of trifocus and SDF ensures optimal catch performance and false alarm immunity.

In addition, all the Bosch Professional Series Intrusion Detectors are certified by an accredited lab to the latest EN50131 standards.