A fiber optic probe is a form of technology that uses fiber optic bundles to perform measurements. The technology is based on the emission and reception of light.
The probes are usually designed with various configurations of fiber optic bundles and can be made in numerous sizes and shapes. Typcially, a probe will have a bundle of emitting fibers and a bundle of receiving fibers. The light is output at a certain power and voltage towards a surface. When the light reaches the surface, it is reflected and scattered. The receiving fibers then pick up the reflected light and return a voltage signal to the processor. The magnitude of this voltage can then be converted to a distance measurement, based upon a calibration curve for the particular probemodel.
With many probes, it is necessary to calibrate to a known zero point, and then make measurements with regard to that position. However, if additional bundles of receiving and transmitting fibers are used, it is possible to develope a probe that is self-calibrating. This allows for much quicker and more flexible measuring situations.
Fiber optic probe technology allows for many advantages. It is superior to contact measurement because it does not physically interface with the surface and cause movement of the part. Since the measurement is performed with light, fiber optics are very capable of producing fast and repeatable measurements. Additional advantages include that the probes can come in a variety of shapes and sizes, allowing for the ability to measure difficult and hard to reach locations. It is also possible to make measurments with single fiber if necessary.
In addition to distance measurements, fiber optics can be used to perform other measurements as well. Temperature and strain measurements are other application possibilities.
Props to smartalix for pointing out the single fiber application. Check out www.smartalix.com