You can measure resistance of an electronic circuit using an ohmmeter, which is a standard feature found in most multimeters. The procedure is simple: First, you disconnect all voltage sources from the circuit; then, you touch the ohmmeter’s two probes to the ends of the circuit and read the resistance (in ohms) on the meter. Resistance is measured in units called ohms, represented by the Greek letter omega (ω). The standard definition of one ohm is simple: It’s the amount of resistance required to allow one ampere of current to flow when one volt of potential is applied to the circuit.