Tracer

Tracer may refer to:

• Histochemical tracer, a substance used for tracing purposes in histochemistry, the study of the composition of cells and tissues
• Isotopic tracer, a substance with an isotope that has been enriched to a greater level than that found in nature
• Radioactive tracer, a substance containing a radioisotope that is used for tracking purposes
• Flow tracer, any fluid property used to track fluid motion:
  • Dye tracer
  • In the ocean, salinity, potential temperature, and the concentration of many different chemical compounds
• Tracer ammunition, special bullets that burn brightly to enable the shooter to follow the bullets' trajectories
• Mercury Tracer, an automobile
• TRACER (cosmic ray detector) (Transition Radiation Array for Cosmic Energetic Radiation), a balloon-borne cosmic ray detector
• TRACER (Tactical Reconnaissance and Counter Concealment Enabled Radar) is a mid-range, long wavelength synthetic aperture radar system developed by the United States Army.
• Grumman E-1 Tracer, a carrier-borne AEW aircraft used by the United States Navy in the 1960s.