Clean all connectors and the detector port of your optical power meter. Connect the power meter to a calibrated light source at the required wavelength (such as 1310 nm or 1550 nm). Zero the meter according to the. EXFO can help save both time and costs with an automated calibration test system that is designed for the verification of power meters, attenuators, sources and optical time-domain reflectometers (OTDRs).