To use a power meter for fiber optic testing, always clean connectors first with lint-free wipes or click-to-clean tools. Select the correct wavelength and set your reference. You measure optical power in dBm or insertion loss in dB. Consistent procedures ensure accuracy. Verify light travels from. Monitoring optical power levels is essential because even slight deviations can significantly affect the stability, quality, and availability of optical transmission services. Optical networks rely on precise power balance—too much power can damage receivers or distort signals, while insufficient. To test transmitted power in sfp optical modules, you use an optical power meter to get exact results. Many sfp modules also have DOM/DDM, which lets you see digital diagnostic monitoring data on network equipment.