The Pocket Fiber Testers are simple, low-cost solutions for checking multimode fiber optic communications cables and connections. They are easy to use and small enough to fit in a shirt pocket or tool kit. Test cables before and after installation with the easy-to-read bar graph indicator. The readout is a measure of absolute optical power labeled in -2 dBm steps. The units are available with ST or SC connectors. The fiber checker frees up more costly test equipment when you just need a quick operational test. The D410 is both the fiber light source and power meter built together. It can be used by itself, looping both ends of the fiber cable into the unit, such as checking a spool or an un-installed fiber cable. For installed fiber or long runs, the D410 can be used in tandem with the D420 to provide a remote light source and use the D410 as the power meter only. Alternatively, the D420 and D430 are separated light source and power meter, respectively and are used together at opposite ends of the fiber optic cable.

To use the Pocket Fiber Tester, remove the protective covers from the fiber connectors. Join your fiber to the tester and turn it on using the slide-switch on the side. The tester’s bar graph indicator gives you an absolute measurement of the optical power coming into the its receiver. This means that in order to estimate the LOSS IN YOUR FIBER, you need to know how much power is being launched by the tester and then subtract the power being received back.

If the power led is dim or won’t light, it may be time to replace your battery. You can check this by simply pointing the tester at a light source and verifying that the bar graph lights up all the way as you approach the light. Another test is to connect a short piece of “known good” 100 micron fiber between the transmitter and receiver. This should also yield a “full scale” readingon the bar graph. If not, then try replacing the 9-volt alkaline battery.