Photoswitch, M18 RFLX NPN - 

The S51 series solution in M18 Photoelectric Sensor with a wide range of functions and operating distances. S51 sensors are available with either axial or radial 90º optics. In both cases, the optic head and lenses do not project beyond the external 18mm diameter of the sensor housing. The diffuse-proximity model has a 10cm fixed operating range with a wide emission spectrum. Also available is a version with a 1 to 40cm adjustable operating range. Standard retro-reflective models have an operating range up to 4m. The polarized retro-reflective models, used for reliable detection of reflective objects, are fitted with a sensitivity adjustment and have a 3.5m operating range. The through-beam models, used for longer operating distances, reach 18m. The normally open output is activated in light mode in proximity models and in dark mode in retro-reflective models.