|a chattering or flighty, light-headed person.|
|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
|1.||a person or thing that traces|
|2.||a. a projectile that can be observed when in flight by the burning of chemical substances in its base|
|b. ammunition consisting of such projectiles|
|c. (as modifier): tracer fire|
|3.||med any radioactive isotope introduced into the body to study metabolic processes, absorption, etc, by following its progress through the body with a gamma camera or other detector|
|4.||an investigation to trace missing cargo, mail, etc|
tracer trac·er (trā'sər)
A substance, such as a dye or a radioactive isotope, that is introduced into and followed through a biological or chemical process, by virtue of its radioactive signature, color, or other distinguishing physical property, thus providing information on the course of the process or on the components or events involved.
An instrument used in dissecting out nerves and blood vessels.
|tracer (trā'sər) Pronunciation Key
An identifiable substance, such as a dye or radioactive isotope, that can be followed through the course of a mechanical, chemical, or biological process. Tracers are used in radioimmunoassays and other laboratory testing. The use of radioactive iodine, for example, can give information about thyroid gland metabolism. Also called label.
detectable substance added to a chemical, biological, or physical system to follow its process or to study distribution of the substance in the system. Tracer dyes have long been used to follow the flow of underground streams. Incendiary rounds included at intervals in a belt of machine-gun bullets make the paths of the bullets visible. In scientific work, the use of tracers has increased and, because of the sensitivity of modern methods, has helped solve many problems. Particularly effective modern methods utilize isotopic tracers. See isotopic tracer.
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