Power meter measurement in five steps: 1) Clean the meter port and the patch cord. 3) Reference the source through a launch cord (for insertion loss only). 5) Read the value, and compare. This guide walks through the full procedure -- from cleaning the connector to interpreting the result -- so your measurements are trustworthy on the first try. 3). 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. Turn on the optical power meter (OPM) using the power button. The basic process is straightforward: turn the meter on, set it to the correct wavelength, clean your connectors, plug in, and read the. This is your "QuickStart" guide to testing optical power in fiber optic communications systems with a fiber optic power meter. We'll give you the basic information you need and provide some printable references.