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. In this video, Bird walks you through the process of using a wattmeter to measure both transmitter output power and VSWR (Voltage Standing Wave Ratio). Understanding the principles. These meters provide a precise and reliable method for quantifying the power level of light across various wavelengths, making them essential instruments in the testing and calibration of optical systems.