Yokogawa
Open a Yokogawa OTDR file in your browser
Measurements from AQ series instruments read right here — including the nested SOR that until now only the vendor's own AQ7932 would open.
Eighty-seven AQ files sit in our corpus and are checked on every build.
What we actually read
Every format was worked out from real instrument files, not from a description in a specification.
.sor from AQ instruments
The AQ1000, AQ7280 and their neighbours write Telcordia, read by the native parser. That file can also be edited and saved back as .sor.
Nested SOR
Some Yokogawa files are containers with a real .sor inside. We find it in there and open it — from the outside it looks like an ordinary trace.
Then work, not just viewing
Cursors, events, loss over a span, overlaying neighbouring measurements and saving back to .sor. All of it free.
There is nothing to download
People look for the Yokogawa viewer as an installer — "yokogawa otdr viewer free download". There is nothing to install: the page opens by link on macOS, Windows and Linux, from a tablet and from a phone, and needs no account. What happens to the file you open is stated plainly in the terms of use.
What we do not read yet
Early Yokogawa and Ando instruments have extensions of their own — .TRD, .TRB, .TRA, .AOD — and we hold no sample of any of them. We name them here honestly instead of promising: if you have such a file, send it to ilya@cheredin.ru and we will work the format out from it.
Nearby
OTDR Master is an independent service. Yokogawa and AQ are trademarks of Yokogawa Electric Corporation; we are not affiliated with the company and do not ship its software — we only read files its instruments write.