This Turck inductive proximity sensor is manufactured with a nonshielded coil, designated by "Ni" in the part number. Nonembeddable (nonshielded) units require a metal free area around the sensing face. Because of possible interference of the electromagnetic fields generated by the oscillators, minimum spacing is required between adjacent or opposing sensors. It is good engineering practice to mount sensors horizontally or with the sensing face looking down. Avoid sensors that look up wherever possible, especially if metal filings and chips are present.
It's rated operating distance is 8 mm and it's a Uprox sensor, which are indicated by the "8U" in the part number. A Uprox sensor is an inductive proximity sensor that detects all metals at the same range. Uprox sensors are inherently weld-field immune, operate over a wider temperature range and have a higher switching frequency than standard inductive sensors. The "M12" section of the part number means the sensor is partially threaded and the housing diameter is 12 mm. The "AP6X" means the sensor is normally open, uses PNP (current sourcing), needs 10-30 VDC and has 1 LED. Lastly, the "H1141" means this Turck sensor has a straight eurofast (M12) connector, with 4 pins and standard wiring.