While there are many ways to measure membrane potential, two common ways are known as voltage clamping and patch clamping.

1.) Voltage Clamping: Voltage clamping is the process of "clamping" or setting the membrane potential to match a particular voltage, known as the "command potential." This is accomplished by placing an electrode into the interior of the axon that measures the membrane potential of the axon. This electrode is connected to a voltmeter, which measures the potential difference between the interior of the axon and the surroundings of the axon. Finally, information about the potential difference (i.e., membrane potential) is sent to a voltage clamp amplifier, which compares the current membrane potential with the command potential and "injects" current such that the membrane potential matches the command potential.

2.) Patch Clamping: Voltage clamping can not only help us set a membrane potential, but it can also tell us how much current is flowing through Na+ ion channels during an action potential. A more precise way to measure this might be through patch clamping. A patch clamp uses a voltage clamp to measure the flow of current through a tiny patch of membrane. There are many different patch clamping techniques that can be used to measure currents pulsing through different patches of membrane, from whole cellular membrane to a single receptor on the cellular membrane.