STEINEL’s high-frequency (HF) sensors are ideal for areas such as toilet blocks, offices and corridors, as they can detect movement even through glass or thin walls. Unlike passive infrared (PIR) technology, which relies on heat radiation from people, HF sensors operate using electromagnetic waves. This enables them to reliably detect movement even when the line of sight is obstructed. Whilst PIR sensors require a direct line of sight, HF sensors offer greater flexibility in more complex room layouts. Another advantage of HF technology is that it is unaffected by external factors such as light or temperature conditions. Concealed installation makes them particularly vandal-proof, and models featuring Bluetooth technology allow for smart control via an app. Compared to PIR and ultrasonic sensors, RF sensors are the better choice, particularly in sensitive areas with many obstacles where discreet installation is required.