When the pulse width is increased on an OTDR, what is the result?

Increasing the pulse width on an Optical Time Domain Reflectometer (OTDR) effectively enhances the instrument's overall measurement range. This occurs because a longer pulse provides more energy to the signal being sent down the fiber, allowing it to travel further before any return signals are detected.

As the pulse travels, it interacts with the fiber and any connectors, splices, or faults present. A longer pulse width also helps in reducing the effects of scattering and attenuation, which are more prevalent in shorter pulses. Thus, the ability to detect reflections and other optical events is enhanced over longer distances, which is directly tied to increased range capabilities.

While changing the pulse width can impact other aspects, such as resolution and dead zones, the fundamental outcome of increasing pulse width is an extended measurement range, enabling the OTDR to analyze longer lengths of fiber optic cables effectively. This nuanced understanding of how pulse width interacts with the OTDR's capabilities illustrates why increasing it results in an increase in range.