The optical fiber amplifier is a device where signal light near 1.55 micrometers is amplified by stimulated emission of the exited erbium ions as the signal passes through the erbium doped fiber. The critical properties of erbium doped fiber amplifiers are the output power, gain, and noise. These amplifier parameters should be measured as a function of wavelength. For this reason we have constructed a measurement system that consists of a tunable signal source, fast chopper, detectors, and microcomputer. This amplifier measurement system can be used to characterize amplifier properties as a function of wavelength and input or output powers.