An optical fiber multimeter (OFM) is an essential handheld tool for fiber optic technicians (it can be compared to multimeters used by electrical technicians). OFMs quickly measure multiple key optical parameters such as loss (dB), optical return loss (dB), length (meters) and power (dBm). They help technicians verify optical link health and troubleshoot potential issues.

The interpretation of those key parameters allows technicians to diagnose basic issues. For example, no power indicates discontinuity; low power or high IL means excessive attenuation; and high ORL shows excessive reflectance.

The source and location of issues can be determined with further analysis and frontline technicians would need additional tools (e.g., VFL, fault locators or OTDRs) to find out if high IL is caused by a bad splice or a macrobend, or if the high ORL is due to a dirty connector or bad mating.  

Top-shelf OFMs include fault-finding capabilities, i.e., when issues are suspected during the verification of the link health, the unit locates and diagnoses common faults automatically in addition to identifying the causes. Such OFMs empower technicians of any experience level to perform on-the-go troubleshooting in addition to the end-to-end sanity check of the installation.