1. An instrument that can measure current and voltage.
2. Any electrochemical technique in which a faradaic current passing through the electrolysis solution is measured while an appropriate potential is applied to the polarizable or indicator electrode; for example, polarography.
3. A method of determining the chemical makeup of a sample substance by measuring electrical activity, or the accumulation of chemicals, on electrodes placed in the substance.

Voltammetry is often used to determine the amount of trace metals and toxins in water or other solutions.