Electrostatic field detectors, the seaside, and the desert wind? [PERIFELD-M security fence]

In the early 1960s, the first ideas were developed by leading companies in Germany to design an intrusion detection system following a capacitance measurement principle. In 1982, Siemens AG was the first company in this market which analysed all outdoor influences and recognised the essential problems which cause any classic capacitive or electrostatic detector to suffer from high unwanted false alarm rates. The result was that, already in 1984, a complete new peripheral hardware design, with a very high electrical and capacitive stability, was created by Siemens AG which remains state-of-the-art. Nevertheless, even if this high-grade material is installed, it can happen in certain cases that apparently invisible peripheral influences are the cause of important electrical effects. This paper describes a practical case experienced in 1999 where a coincidental combination of seaside conditions and a local desert wind strongly interfered in the physics of a capacitive electrostatic field detector.