
A unit of electric potential equal to one thousandth of a volt.The millivolt (mV) is a unit of electric potential difference equal to one thousandth of a volt. It is commonly used to measure small voltages in electronic circuits, biological signals, and electrochemical processes. For example, the electrical activity of the human heart produces signals on the order of millivolts, as do many sensors and transducers.
The volt is named after Alessandro Volta, who invented the voltaic pile in 1800. The millivolt prefix was adopted with the metric system in the 19th century.
The millivolt is defined by the SI system as 10^-3 volts. A volt is the potential difference that drives one ampere of current through one ohm of resistance. In practice, millivolt-level signals are measured using sensitive voltmeters or amplifiers, which boost the small signal to a readable level.
Millivolts are used in electrocardiography (ECG) to measure heart signals, in thermocouples for temperature sensing, and in audio equipment to specify microphone output levels.
A typical AA battery produces 1.5 volts, which is 1500 millivolts — enough to power a small LED, but the voltage across a single neuron in your brain is only about 70 millivolts.





