Diffuse sensor with background suppression - Balluff
Photoelectric technology overview - ifm
Fundamentals of Photoelectric Sensors
Diffuse Sensor
O6H214 - Diffuse reflection sensor with background suppression - ifm
TNI CONTROLS M18 Diffuse Photoelectric Sensor DC Input, 10 to 30VDC / 200mA, 2mtr Long Cable ABS Body Photoelectric Switch Pack of 1Pc's TYPE:M18-DC-PNP-NO (RANGE: 500mm) : Amazon.in: Home Improvement