The Illustrated Dictionary of Electronics - Loscha

adiolocator • radio spectroscope 579radiolocator See RADAR.radiological system See X-RAY THERAPY SYS-TEM.radiologist A specialist skilled in RADIOLOGY.radiology The science embracing the theory anduse of X rays and radioactive substances in thediagnosis and treatment of diseases and ailments.radiolucency 1. The property of a material that allowsionizing radiation to pass through it with littleor no absorption. 2. The extent to which amaterial transmits ionizing radiation.radioluminescence Visible light emitted from a radioactivematerial. A good example is radium; itwas once used on wristwatch dials so that theycould be seen in the dark.radiolysis Chemical decomposition brought aboutby radiation.radioman A radio technician or operator.radio map A map of a geographic area, on whichlines are drawn connecting measured points ofequal field strength for signals from a radio stationat the approximate center of the area.radiometeorograph See RADIOSONDE.radiometer A device for detecting and measuringthe strength of radiant energy. One form consistsof a set of vanes blackened on one side andmounted on pivots in a partially evacuated glassbulb. Visible light or infrared causes the vane assemblyto rotate, the speed being proportional tothe intensity of the light.GlassenveloperadiometerLightradiometry The science and art of measuring radiationin the infrared, visible, and ultraviolet regionsof the electromagnetic frequency spectrum.Compare PHOTOMETRY.radio micrometer See MICRORADIOMETER.radionavigation The use of radio apparatus, usuallyin conjunction with computers, by personnelaboard moving vessels, for the purpose of plotting,correcting, and maintaining a course. The intersecting-linemethod is simplest. Two or threeland-based transmitters are needed. Their locationsmust be accurately known. A directionfindingdevice on the vessel is used to determinethe bearings of each of the transmitters. Aircraftradionavigation can be performed with the aid ofradar. The most sophisticated radionavigationtechniques employ the Global Positioning System(GPS). Computers are used to project the courseof a craft based on its current position, its speed,and the direction of its movement. Course correctionsare made by choosing the desired courseand having the computer calculate speed and/ordirection changes. Compare RADIOLOCATION.radio net A group of radio stations operating togetherin an organization, often on or near thesame frequency.radio network See RADIO NET.radio operator A technician licensed to operate atransmitter in the radio, television, or radar services.radiopaque Opaque to X rays or other ionizing radiation.Compare RADIOPARENT.radioparent Transparent to X rays or other ionizingradiation. Compare RADIOPAQUE.radiophone See RADIOTELEPHONE.radiophoto A photograph transmitted and receivedby radio. Also see FACSIMILE.radio pill See ENDORADIOSONDE.radio prospecting The use of radio-frequency devicesto locate underground or underwater metalsand mineral deposits. Also see METAL LOCATOR.radio range A radio station providing navigationalaid to airplanes.radio receiver The complete apparatus that selects,amplifies, demodulates, and reproduces aradio signal for purposes of communication, asdistinct from facsimile receiver, remote-control receiver,telemetry receiver, television receiver, etc.radiosensitivity 1. The property of being sensitiveto ionizing radiation. Most photographic filmshave this property. 2. The extent to which a substanceor device is sensitive to ionizing radiation.radio service technician An electronics technicianskilled in the repair and maintenance of radioequipment—especially receivers.radiosonde A balloon-carried combination of radiotransmitter and transducers, for sending to aground monitoring station signals revealing suchatmospheric conditions as temperature, humidity,and pressure. It is used mainly for gatheringmeteorological data at high altitudes.radiosonobuoy See SONOBUOY.radio spectroscope A device used by radio astronomersto obtain the radio-frequency profile ofa distant star or galaxy. It generally consists of a