Fiber Optic Probes for In-Process Control
This chapter presents a unique gauging sensor utilizing fiber optics which lends itself to both on-line and off-line measurement applications. The commercial development of efficient and cost-effective optical fibers and peripheral components for the telecommunications industry during the past decade has spawned a new generation of physical measurement transducers and sensing systems which utilize light energy as the primary signal transmission, conversion, and detection mechanism. Fiber optic lever displacement sensors utilize adjacent pairs of light-transmitting and light-receiving fibers. The basis for the operating mechanism is the interaction between the source fibers and the field of view of the receiving, or detector, fibers. Since most in-process measurement and control applications require ease of installation, low cost, and reliability, the majority of fiber optic systems in industrial use today employ intensity-modulated devices because their inherent simplicity meets the needs of most industrial applications and their performance often rivals that of the more complex techniques.