Editing Optical time-domain reflectometer (section)

==Types of OTDR-like test equipment==

The common types of OTDR-like test equipment are:
# '''Full-feature OTDR''': 
#:Full-feature OTDRs are traditional, optical time domain reflectometers. They are feature-rich and usually larger, heavier, and less portable than either the hand-held OTDR or the fiber break locator. Despite being characterized as large, their size and weight is only a fraction of that of early generation OTDRs. Often a full-feature OTDR has a main frame that can be fitted with multi-function plug-in units to perform many fiber measurement tasks. Larger color displays are common. The full-feature OTDR often has a greater measurement range than the other types of OTDR-like equipment. Often it is used in laboratories and in the field for difficult fiber measurements. Most full-feature OTDRs are powered from AC and/or a battery.
# '''Hand-held OTDR and Fiber break locator''': 
#:Hand-held (formerly mini) OTDRs and fiber break locators are designed to troubleshoot fiber networks in a field environment, often using battery power. The two types of instruments cover the spectrum of approaches to fiber optic plant taken by communication providers. Hand-held, inexpensive OTDRs are intended to be easy-to-use, light-weight, sophisticated OTDRs that collect field data and perform rudimentary data analysis. They may be less feature rich than full-feature OTDRs. Often they can be used in conjunction with PC-based software to perform data collection and sophisticated data analysis. Hand-held OTDRs are commonly used to measure fiber links and locate fiber breaks, points of high loss, high reflectance, end-to-end loss, and Optical Return Loss (ORL).
#:Fiber break locators are intended to be low-cost instruments specifically designed to determine the location of a catastrophic fiber event, e.g., fiber break, point of high reflectance, or high loss. The fiber break locator is an opto-electronic tape measure designed to measure only distance to catastrophic fiber events.
#:In general, hand-held OTDRs and fiber break locators are lighter and smaller, simpler to operate, and more likely to employ battery power than full-feature OTDRs. The intent with hand-held OTDRs and fiber break locators is to be inexpensive enough for field technicians to be equipped with one as part of a standard tool kit.
# '''RTU in RFTSs''': 
#:The RTU is the testing module of the RFTS described in Generic Requirements for Remote Fiber Testing Systems (RFTSS).<ref name= "Telecordia Jan 2000">{{Citation|title = Generic Requirements for Remote Fiber Testing Systems (RFTSs)| publisher = Telcordia (Ericsson Inc)| date = January 2000 | url = http://telecom-info.njdepot.ericsson.net/site-cgi/ido/docs.cgi?ID=SEARCH&DOCUMENT=GR-1295&| access-date = 15 April 2015}}</ref> An RFTS enables fiber to be automatically tested from a central location. A central computer is used to control the operation of OTDR-like test components located at key points in the fiber network. The test components scan the fiber to locate problems. If a problem is found, its location is noted and the appropriate personnel are notified to begin the repair process. The RFTS can also provide direct access to a database that contains historical information of the OTDR fiber traces and any other fiber records for the physical fiber plant.
#:Since OTDRs and OTDR-like equipment have many uses in the communications industry, operating environments vary widely, both indoors and outdoors. Most often, however, these test sets are operated in controlled environments, accessing the fibers at their termination points on fiber distribution frames. Indoor environments include controlled areas such as central offices (COs), equipment huts, or Controlled Environment Vaults (CEVs). Use in outside environments is rarer, but may include use in a manhole, aerial platform, open trench, or splicing vehicle.