If so, have you ever spotted a defective fiber? Why do you test incoming cable? Do you keep all the results?
As mentioned, cable quality is very, very high among our approved vendors. They ship tens of thousands of good ADSS reels without shipping a defective reel. All of the cable is 100% tested with OTDRs and documented at the factory before shipping. Incoming acceptance testing protects the cable purchaser from damage by the shipping company.
Some users don't test fiber cable on incoming inspection and we think that's a calculated risk to save time and money. We recommend taking this extra step and documenting the results; doing so protects the utility if a contractor subsequently damages the cable ("we didn't do that -- the trucker must have damaged it!")
If by some chance, you did receive a defective reel of cable on incoming inspection in the last 5 years, we'd be interested to hear about it and who the vendor was.
Finally, we should note that OTDRs are good at spotting point fiber defects on incoming reels. They are less accurate at measuring dB/km -- you may often find your measurement of dB/m varies from the factory's by 0.02 dB or so. Keep this in mind if you're trying to measure vendor performance against dB/km specifications.