Measuring 30 x 30 x 15 mm, Series 3131 is immune to color, shape, and surface texture of background beyond set target detection point. Background suppression can be adjusted in small increments down to 15 mm, and sensors have tiny blind zone, enabling targets to be sensed down to 1 mm from lens. Immune to stray light sources, sensors have 500 Hz operating frequency, 200 mA switched current rating, 10–36 Vdc operating supply voltage, and stable sensing range from 25–55°C.