This guide covers when to calibrate, what calibration actually involves, what a legitimate certificate looks like, and how to verify your meter's accuracy between calibrations. Send the meter to a NIST-traceable calibration lab. The lab measures the meter against. An optical power meter is the most common type of test equipment used to support fiber optic system. We explain the measurement standards, systems, methods, and uncertainties related to. Below are general answers on how to operate, maintain, and calibrate an optical fiber ranger from the list of GAO Tek's optical power meters. Power On: Ensure the device is charged or properly connected to a power source.