The Cutler-Hammer E51DP4PD Photoelectric Head, Diffuse Reflective, is a sensing head used in automation to detect objects by diffuse reflection of light. Also listed as Cutler Hammer E51DP4PD, it refers to the same part under alternate branding. In the diffuse-reflective configuration, the head functions as the sensing element in a photoelectric sensor system, detecting targets based on reflected light.
