Aside from flashlight you could plug it on the sending side and see if
light makes it through. Just don't look directly into it. You should
reflect it on your hand or a piece of paper. That is, if you like
having eye sight.
Bill
Len Hammond wrote:
In my last full time gig, I had an OmniScanner II for Ethernet. It had
an option to add a Fiber tester to the device. The OmniScanner
retailed for about $8500 & I bought it new in 2000 for $5000 and the
Fiber option was about $1500 and I didn't get one. It had TDR for
copper and I am assuming that it would work for the fiber as well.
Great device but a bit pricy if you don't need one often. Wish they
would have let me take it with me when I left. I'm sure no one left
there knows how to use it. I could use it more often now than when I
was there. Many small clients with wiring issues. Omni was bought by
Fluke some time in 2004 to 2006 and the Omni technology was
incorporated into the current Fluke network testers.
The last piece of fiber I pulled we did test with a flashlight. Mostly
to see if we broke it during the 600 foot pull and to get the polarity
right on the connectors. The flashlight worked great although we
didn't get any other data telling just how good the fiber was going to
work but typically fiber either works or it doesn't. Not a lot of grey
area.
Len Hammond
CSI:Hartland
[email protected] <mailto:[email protected]>
On Wed, Sep 23, 2009 at 9:33 PM, Ben Scott <[email protected]
<mailto:[email protected]>> wrote:
On Wed, Sep 23, 2009 at 6:32 PM, Sean Martin
<[email protected] <mailto:[email protected]>> wrote:
>> Can't you just shine a light through one end and see if theres
light on
>> the other end? ;-)
>
> Does it actually work?
That will tell you if the cable has been completely snapped, e.g.,
kinked hard, pinched in a door, etc.
It won't tell you the condition of the tip. The tips can get
scratched, especially if they're put in a pile without a cable condoms
on the end. A scratched tip could still pass visible light but not be
good for data.
The tools I've seen used for this are a power meter (already
described) and a handheld microscope. The scope is basically just a
flashlight and a special fitting to hold the fiber. You peak in the
end and examine the tip. A clean tip looks like a solid white circle.
A scratched or damaged tip has lines or other black/gray marks.
> ... sharp bends in fiber can
> cause problems because those light impulses can end up being
reflected out
> of order ...
I can't confirm or deny that. The two cautions on bends I've heard
are: (1) Fiber is glass. A sharp enough bend will snap the fiber in
half. After that it's dead. (2) The more you bend it without
breaking, the more of the light energy will be absorbed by the wall
instead of propagating down the fiber. Eventually the loss (either in
one spot, or cumulatively) goes too high and the receiver can't "see"
the signal. This can at least be fixed by straightening the line.
> Are my concerns valid? Is there a reasonably priced device to
verify the
> integrity of a fiber cable, or am I just going to have to try
the flash
> light trick and then plug n pray?
Google suggests power meters can be had for under $300. I have no
idea what a good one costs. :)
-- Ben
~ Finally, powerful endpoint security that ISN'T a resource hog! ~
~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
~ Finally, powerful endpoint security that ISN'T a resource hog! ~
~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
