Which method measures the highest voltage in a circuit?

The method that effectively measures the highest voltage in a circuit is peak detection. This technique is specifically designed to identify the peak voltage levels within an electrical signal. Peak detection works by capturing the maximum value that the signal reaches during its oscillation or fluctuation, making it particularly useful in applications where voltage levels can vary significantly, such as in alternating current (AC) circuits.

Direct measurement typically refers to measuring the current voltage level at a given moment, which would not necessarily reflect the highest voltage experienced in a circuit. Reference measurement is more about comparing values against a known standard, and analog measurement deals with continuous signals rather than capturing specific peak values. Therefore, peak detection is the most appropriate answer, as it directly targets the maximum voltage encountered within the circuit dynamics.