During the basic OTDR test, the pulse generated by the pulse generator drives the LD to generate optical pulse, which is injected into the optical fiber to be measured through the directional coupler.The light pulse emitted into the fiber is scattered because of impurities and bubbles inside the fiber, and some of the light is called BACK scattered light. Together with the FRESENL reflected light generated by the uneven end face of the fiber, it is reflected BACK to the coupler and injected into the photodiode for conversion into electric pulse wave.This reflected light, because very weak, so repeated transmission, collection, superposition, amplification, average processing, and then the waveform displayed on the CRT.It has the characteristics of high dynamic range, small volume and high horizontal resolution.The physical location of the optical fiber event points is determined by OTDR.

Module parameters:

Wave lenth：1550nm±20nm、1625nm±20nm、1650nm±20nm；

Dynamic range：42dB、40dB、38dB、36dB、34dB、30dB；

Pulse width：5ns,10ns,20ns,40ns,80ns,160ns,320ns,640ns,1.28us,2.56us,5.12us,10.24us,20.48us；

Event deadzone：2 m (Pulse width 10ns, reflecting event peak no more than 10dB)；

Attenuation deadzone：12m（10ns pulse, unsaturated）；

Minimum sampling interval：0.125m；  Maximum number of samples：32k；

Ranging accuracy：±（1m+5×10-5×distance+Sampling interval）

Optical connectors：LC/PC；

Operating Temperature：0°C to +50°C；

Storing Temperature：-40°C to +70°C；

Humidity：≦ 85%RH；