The sensing section of a Fiber Unit has no electric circuits. This makes it highly reliable even under severe environmental conditions, such as temperature, vibration, shock, water, and electrical noise conditions. Easy Installation The Fiber Unit can be installed close to the. Depending on the application, fiber may be used because of its small size, or because no electrical power is needed at the remote location, or because many sensors can be multiplexed along the length of a fiber by using light wavelength shift for each sensor, or by sensing the time delay as light. A fiber optic sensor measures physical quantities based on how they modulate the intensity, spectrum, phase, or polarization of light traveling through the optical fiber system. An optical sensor converts light rays into electronic signals, similar to a photoresistor which changes resistance based. Fiber optic current sensors are revolutionizing the way electrical currents are measured, providing high sensitivity, immunity to electromagnetic interference (EMI), and the ability to function in harsh environments. Radiation absorption creates electronic excited states that are trapped by localized defects for extended periods of time. Heating the material enables the trapped states to interact with phonons and decay into lower-energy. Since fiber-optic cables do not contain electronic components, fiber-optic sensors are particularly suitable for applications in confined spaces, harsh environments or where other sensors cannot be used.