Azbil Model HPF-47 Fiber Units for Small Parts Passage Detection provide reliable detection of small parts going through the pipe. Wire lead-out follows the pipe, allows a smaller footprint. By changing the attachment, the width of the detection area can be adjusted to match the pipe diameter. Highly bend-tolerant optical fiber cables are used for operation inside a moving device. Unaffected by light-level changes or stain buildup, the Model HPF-47 Fiber Units for Small Parts Passage Detection provide stable detection. In addition, since the light level differentiation signal is transmitted to a second output, the model provides advanced notice of sensitivity limitations.