.sor
How to open a .sor file
Drop the file into the window and you see the trace, the events and the measurement's parameters. Both versions of the standard, every instrument's dialect, nothing to install.
The short answer to "how do I open it" is: by link. Below is what the file is and what you can do with it.
What the file is
.sor is a Standard OTDR Record, the trace format written by instruments from nearly every manufacturer.
Bellcore and Telcordia
The GR-196 standard exists in two versions, 1.x and 2.x, and instruments still write both. Both are read; you do not have to tell them apart.
More than the curve inside
Refractive index, wavelength, pulse width, operator, comment and the instrument's own event table. All of it is on screen next to the trace.
A file with no extension is one too
Some vendors' software saves a measurement with no extension at all. The format is recognised by content, so such a file opens like any other.
There is nothing to download
"sor file viewer download", "sor file open software" — the usual search is for an installer. There is nothing to install and no sign-up: the page opens by link on any system. What happens to the file you open is stated plainly in the terms of use.
And what to do with it next
Measure a span with cursors, correct events and metadata, trim the tail, recalculate for a different refractive index — and save back to a .sor that opens in the instrument's own software. Every edit is written inside the saved file: what was changed and when stays visible to whoever opens it later.
Nearby
File would not open? Send it to ilya@cheredin.ru — we will work the format out from your file and teach the service to read it.