Here at Offutt, we've started doing the fiber for ACC..I've been able to acquire some alignment procedures for the Noyes, Rifocs/Tempo, and some other optical power meters..
If anyone needs help, email me. A lot of stuff I've seen is close to the tolerance, or just flat out gone..
Mike
On the subject of fiber optics, I have a question that I have yet to get a straight answer from anybody, maybe you could help me... We've been seeing more and more hand held fiber optic test tools at our (civilian) cal lab, such as optical power meters, light sources, return loss meters, attenuators, optical time domain reflectometers, etc. We usually ship them off to their respective manufacturers to be calibrated, but would like to start calibrating them in-house. What I'd like to know is what basic instruments and accessories would I need to have on hand to calibrate the majority of fiber optic test tools? I have access to GIDEP and have seen various T.O.s for different fiber optic meters, but to wade through them all to identify what equipment is common to calibrating each meter would be tedious. Is there a "catch-all" T.O. that specifies what to use (much in the same way T.O. 33K1-4-716-1 covers about 4 dozen different multimeters)? Thanks...
Scott P.
FO procedures
K4-394 is one of the main ones.
Equipment Needed:
Sources: IAW the Air Force, you just need a calibrated Optical Spec An.
Optical Power meters: you need sources charted by the OSA, an optical attenuator and a precision power meter (TAR of as little as 1:1 allowed but meters are limited to +/- 0.3 to 0.5 dB)
OSA: three charted (ICO) laser sources.
We are getting ready to build a turn-key optical calibration system. We see this as a growing area for calibration.
If any of you are looking to get into Optical Calibration, or looking to upgrade your existing systems, send me a message. I will periodically send you information on where we are on the project.
Talk to you later.
Quote from: mdbuike on 10-08-2005 -- 09:11:50
Here at Offutt, we've started doing the fiber for ACC..I've been able to acquire some alignment procedures for the Noyes, Rifocs/Tempo, and some other optical power meters..
If anyone needs help, email me. A lot of stuff I've seen is close to the tolerance, or just flat out gone..
Mike
Beyond good quality standards a good video fiberscope is absolutely critical. A good cleaning of connectors can take a lot of borderline conditions and make them spot on again. I've had to train operators as well as engineers on proper connector care.
I totally agree about the cleanliness..Mondays, I totally clean all my cables and connectors, and I ensure all the caps and covers are on.
I've had comments from inspectors on how stable my readings are, usuall repeatable to withing 0.02 db after connecting, disconnecting and reconnecting.
I do wish the USAF would go to a short term charting of the optical attenuator, as this would eliminate multiple connections/reconnections, or get a reliable optical power splitter for each wavelength.
Now as for OTDRs, Fluke has intoduced some that use "smart pulses" so the instrument can be connected in line and not affect the traffic (except for the momentary insertion)..the problem being you cannot use the FOCS1 system to calibrate it, you need calibrated spools (the Fluke pulses don't recognize the FOCS1 pulses and only see the jumper you're using to connect it to the system). I can see a lot of money being spent if other manufacturers go this way. That, and the limitations the FOCS1 system places on what you calibrate..it's accuracy is +/- 1.25 m, so you end up with limitations like "Accuracy +/- 5m per 20km, not to exceed 30m".
I do think spools are the way to go, but the expense during these times.
Mike
Isn't it nice to get a measurement area that is childlike in its development? Little in the way of traceability and a whole lot of smoke and mirrors by the vendors selling the standards and the TI. Add to that a profusion of TMDE that is most like a DMM that begs the question of calibration in the first place. Not for quantative or qualitative measurements. Yes the loss test sets are crap from most of the vendors. My experience of acceptance testing some of the more prolific providers is that they do not pass the expressed uncertainty upon receipt. Most of it is in my world accomplished with a local calibration procedure based upon the manufacturer's manual. As to the DOD and I will include you AF types in that just for good measure. The cognizant authorities have been largely absent in any contribution whatsoever. NSWC, AFMETCAL, USATA, if not dropping the ball are doing a good job fumbling it. If you have any questions check the expiration date on your Focus system. I would have to give the nod to EXFO though I am not a fan of integrated solutions. If it is good enough for Igor its probably good enough for me.
Well, we've only been doing fiber optics here since late 2004..so at 49, I get to learn how this stuff works, never having been stationed at a fiber lab. Most of it's straightforward, and with some contacts and experimentation, I've learned how to adjust most of the power meters out there. Aligning OTDRs seems to be a trade secret held by the manufacturers. Sorces are just that, sources, they work or they don't.
As for traceability, I think NIST is doing alright, and the primary standards lab does well, but sometimes I think the implimentation in the field can have something to be desired. My first couple of years calibrating the meters that the three depots did left me wondering what was going on (like limitations of +/- 2dB). That, and the off hand attitude some of the customers had.
Anyways, I do well, and enjoy it.
Mike
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