The Pepperl+Fuchs NCB4-12GM40-N0 is an inductive proximity sensor designed for reliable object detection in demanding industrial environments. As part of the NAMUR series, this sensor is engineered for use in hazardous areas and safety-related applications, where its robust stainless-steel housing and high protection rating ensure dependable operation . Its core function is to detect metallic objects at a short range without physical contact, making it ideal for position sensing and limit switching tasks.The sensor has a rated operating distance of 4 mm for a standard steel target. The assured operating distance ranges from 0 to 3.24 mm, while the actual operating distance typically falls between 3.6 mm and 4.4 mm . It features a fast switching frequency of up to 1500 Hz, allowing it to detect objects accurately in high-speed applications .The NAMUR technology requires the sensor to be connected to a separate evaluating device (e.g., a safety relay or isolated amplifier). The sensor's internal resistance limits the current flow when a target is detected (≤ 1 mA) and when no target is present (min. 2.2 mA), which is evaluated by the control system to determine the switching state .