A little earlier today I was looking at a 4.5m long, single-mode, patch cable which is terminated with SC/UPC connectors. Its yellow outer jacket states --
Corning Fiber (sic) Optical Cable 9/125 OS2 SM LSZH
There also appears to be a manufacturing batch number printed after the above string.
On the packaging, there is a printed label with a table of the measured insertion and return losses --
| Connector Insertion Loss Return Loss |
| A 0.09 dB 55.3 dB |
| B 0.06 dB 55.4 dB |
At a quick glance, the table shows reasonable values. Then a niggling thought developed that I don't fully understand what is involved . . .
It is a cable, consisting of one fibre, with two ends. As part of the manufacturing process, those two ends are plugged into some gubbins to automagically measure the cable parameters. Is the table telling me that --
- With a standardised laser source at the A-end, a detector at the B-end observes an attenuation of 0.09 dB (the insertion loss) whilst another detector at the A-end observes a reflection (from the B-end) attenuated by 55.3 dB (the return loss)?
Then, logically "swapping ends", the process is repeated.
- With a standardised laser source at the B-end, a detector at the A-end observes an attenuation of 0.06 dB (the insertion loss) whilst another detector at the B-end observes a reflection (from the A-end) attenuated by 55.4 dB (the return loss)?
Having just typed that out, I suspect that the answers are
"yes" and
"yes". But I would appreciate some "words from the wise", please.
