Some

scientific instrument A scientific instrument is a device or tool used for scientific purposes, including the study of both natural phenomena and theoretical research. History Historically, the definition of a scientific instrument has varied, based on usage, laws, a ...

s commonly designated reflectometer are: * Vector network analyser (VNA) *

Optical time domain reflectometer An optical time-domain reflectometer (OTDR) is an optoelectronic instrument used to characterize an optical fiber. It is the optical equivalent of an electronic time domain reflectometer which measures the impedance of the cable or transmissio ...

* Reflectometer (electronics): In ''electronics'', a

directional coupler Power dividers (also power splitters and, when used in reverse, power combiners) and directional couplers are passive devices used mostly in the field of radio technology. They couple a defined amount of the electromagnetic power in a transmiss ...

containing matched calibrated detectors in both arms of the auxiliary line, or a pair of single-detector couplers oriented so as to measure the electrical power flowing in both directions in the main line * Spectrophotometer: in ''optics'', an instrument for measuring the reflectivity or reflectance of reflecting surfaces *

Time-domain reflectometer A time-domain reflectometer (TDR) is an electronic instrument used to determine the characteristics of electrical lines by observing reflected waveforms. It can be used to characterize and locate faults in metallic cables (for example, twisted pai ...

See also