Beam splitters are classified by construction (plate, cube, pellicle, polka dot) and by function (standard, non-polarizing, polarizing, dichroic). Construction determines ghosting, damage threshold, and form factor. Function determines how polarization and wavelength are. A beam splitter divides incident light into reflected and transmitted beams at a specified R/T ratio. For a lossless beam splitter, R + T = 1. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding widespread application in fibre optic telecommunications. They are used for very different purposes. These are denoted „unpolarized“, „non-polarizing“ and „po- larizing“, depending on the functional handling of the polarization of the light to be split.
[pdf] The various protective functions available on a given relay are denoted by standard. For example, a relay including function 51 would be a timed overcurrent protective relay. An overcurrent relay is a type of protective relay which operates when the load current exceeds a pickup value. It is of two types: instantaneous over current (IOC) relay and definite time overcurrent (DTOC) relay.
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