Final answer:
An LCR meter is used to directly measure the capacitance of a capacitor, as it is designed to measure inductance, capacitance, and resistance.
Step-by-step explanation:
To directly measure the capacitance of a capacitor, one would use an LCR meter. This device is specifically designed to measure inductance (L), capacitance (C), and resistance (R). A multimeter can also measure capacitance, but it is typically an additional feature rather than the primary function. An ammeter measures current, and a voltmeter measures voltage, neither of which are used to directly measure capacitance. The capacitance is a parameter that indicates the amount of charge a capacitor can hold per unit of potential difference between its plates and does not depend on the current or voltage alone but on their relationship.