The optical time domain reflectometer is an optoelectronic instrument which is used to characterize an optical fiber. The purpose of the OTDR is to inject a series of optical pulses into the fiber that is tested. Furthermore, the OTDR extracts from the same fiber a light that is reflected back from points in the fiber where the index of refraction is changed.
The OTDR is usually used by cable contractors who test and certify their cable installations. The OTDR measures the estimated length of the fiber and its overall attenuation and it can also be used to locate certain faults. This tool is quite expensive taken into consideration the fact that it is not used too often and in this case SurplusEQ suggests you look into buying a used OTDR. We do offer new OTDR at prices that beat most suppliers.