http://www.discount-low-voltage.com/Tools-Testers/Fiber-Optics-Test-Kits/KIT-Z2S-D285SC I got tired of all the wizards and scientist over explaining every detail when it comes to testing fiber, so I grabbed a light source and power meter out of inventory and made a fiber link with a couple of wall mount boxes so I can easily show you how to do it.
Here's some words from the manufacture regarding this fiber test kit - The Silicon ZOOM II / Dual OWL 850 Test Kit is ideal for LAN managers and installers who need to do simple attenuation tests on their multimode networks.
The Silicon ZOOM II (Zeroed Output Optical Meter) is an economical fiber optic power meter designed to provide accurate testing of multimode fiber cables at 850nm wavelength. The 4-digit 7-segment LCD display shows power readings with a resolution of 0.01dB, power units in dBm, dB, or uW, and battery power level. The Silicon ZOOM II comes configured with a 2.5mm universal port for connection to SC, ST, and other connector types that have a 2.5mm ferrule.
Fiber Optic Performance Standards:
50/125 Fiber @ 850 wavelength 3.5 dB/km - Bandwidth 500 (OM2), 2000 (OM3), 3500 (OM4)
50/125 Fiber @ 1300 1.5 dB/km - Bandwidth 500
62.5/125 Fiber @ 850 3.5 dB/km
62.5/125 Fiber @ 1300 1.5 dB/km
9/125 premise @1310 1.0 dB/km @1550 1.0 dB
9/125 Outside Plant @1310 and 1550 0.5 dB/km