Disclosed is an optical inspection system for inspecting the surface of a substrate. For example, the disclosure describes cured and uncured binders useful in the fabrication of products from loosely assembled fibers. Packets are pipelined through a series of second processing segments to perform a plurality of second sub-operations involved in retrieving packets from the memory structure and preparing packets for transmission. With such an arrangement, of the attenuation of the living tissue 10, non-absorbing attenuation is free from the wavelength. A resistance element of the current sensor is integrated in the outgoing electrical conductor.