We have a good bit of fiber around our campuses, and I’m looking to put some kind of kit together. We’re working on some network updates as part of a larger project, and this would help in figuring out what the cable plants we have in place may be capable of. I’m looking for basic testing/verification type stuff. I’m not looking for certification or termination tools.
About our environment:
Plenty of OM2 50/125 (Multi-mode)
A good bit of OM3 50/125 (Multi-mode)
A little bit of OM4 50/125 (Multi-mode)
Very limited Single-mode 9/125 (going forward when fiber is added it will be single-mode)
Some of our runs are >100 meters. I doubt we have any approaching 1000 meters. Some are probably <100 meters.
A different team has a “DMiotech MTV310 Optical Multi-meter” we’re welcome to use. I can’t find a manual or it online. It may support some VFL and testing of wavelengths (850/1300/1310/1490/1550/1625).
I’d love to be able to test the following:
Verify that a fiber run is passing light, and identify which one it is in a bundle
Gain a simple measurement of the fiber run. Even better if I can get a distance measurement.
Ideally measure signal strength capabilities of the strand. I’ve wondered if measuring light loss and getting a number would enable our team to learn "that number is in no way going to do 10 gigabit)
I’d like to keep the total spend well under $1,000, and would prefer tools that work with both multi-mode and single-mode
I think I’ll need the following, but I’m not sure what else (and even which supplier/brand/option to consider for each of these):
Basic safety equipment: is there particular safety equipment I should consider?
Cleaning supplies: Not sure what I need.
Visual Fault Locator: should tell me if I’m getting light (or if there are breaks) and helps locate the end of a strand. The DMiotech may have this built in. I also see multiple options for this at suppliers (1mW, 30mW) in smaller handheld units, so I’m not sure which one is useful in which situation.
Light source: for generating light that the DMiotech or something else measures?
A standard light meter is likely all you need (with calibrated light sources). That will let you know if the fiber is passing light, and give you an idea if the SNR is sufficient to link. If you need to have high confidence in the link or to get the link distance, then you need an OTDR and those are typically wavelength specific. You can get a quad-wavelength OTDR but those are kind of pricey.
My basic googling says that the DMiotech (which was bought on amazon for probably <$50) can do some measurements and multiple functions…
The light button enables a light that seems to be the equivalent of a VFL. When it’s on the display says “650” instead of a dB rating.
The lambda button changes the wavelength. I believe this changes what it’s measuring. I have choices for 850, 980, 1300, 1310, 1490, 1550, and 1625.
The unit button changes between dBm and ‘low’. Used for seeing the differential between the reference point and the light measured.
The ref button resets the reference point (on the measuring port).
From what you’re saying I think I could get everything (but distance) by getting light source(s) appropriate to the wavelength I want to measure (similar to these)?
Shawn - I keep an “emergency” splice+termination kit on hand (pictured below)
Roughly speaking it includes a decent cleaver, knipex prep tools, tools for both AFL connectors and mechanical splices, a visual fault finder, a light meter and calibrated multi-wavelength light source, all the cleaning gak, and full compliment of SM/MM-50/MM-65 connectors in LC/SC/ST
Took a little over 3k to put together - and I could probably have done it for less had I hunted eBay better. It’s already come in handy a few times and for people with a lot of fiber, it’s not a bad insurance plan.
To your question specifically however - many of the inexpensive light meters and light sources are not very reliable or trustworthy. Doubly so if you need to deal in laser wavelengths (which you do).
Go digging in optical forums and you’ll find vast discrepancies between runs, trouble with the soldered in batteries, or non-stable light sources. Lots of units well reviewed on Amazon/eBay are either bought reviews, or reviewed by people who have never used a unit before and assume if it turns on and gives a number they are good to go.
If you just need to know if one cable or run is working - I don’t think there is a need to buy fancy tools. Although in that case I might question if you need to buy tools at all. Just use a switch and look at onboard diagnostics.
If however you are trying to troubleshoot an intermittent issue. If you need a tool you can pickup long term that you can trust. If you need to do this without breaking the bank - check out the Jonard FLS-55 multi-wavelength light source and the Jonard FPM-70 light meter. I think they sell a bag if you want them packaged together. You should also pickup a calibrated jumper set if you want to be serious about it.
The Jonard are field-use tools commonly proven to be durable and accurate. They take AA batteries so no problem removing them for storage. They can be sent out for calibration over their lifetime. They come with the needed adapters for FC/LC/ST connectors. I think they are the cheapest power meters you can own for a prolonged period and put some trust in the numbers they give you.
Not saying you need to go this way - but I think most reasonably trustworthy options are in this dollar ballpark. -K
Thanks. We definitely have switches and optics already that we’re going to be doing some testing with.
My prior fiber experience has all been Panduit Opticam termination which is a bit of a specific scenario different from this.
The long and short is that we have some short-run OM2 that we’re wanting to test out. We think it could be short enough for some SFP’s we have on hand to do 10 gig (FS.com 850nm 10GSR-85 or FS.com 1310nm 10GLR-31)
I appreciate the insight. I definitely have some options to consider now, including becoming more familiar with the things we have on-hand (the cheap multimeter that includes a light for verifying plant labeling).
I would highly recommend you completely discontinue the notion that you can reliably do 10G on OM2. If it’s a short enough run to be quasi reliable (<300’) it’s a short enough run to replace and if it’s not worth replacing it’s not worth running 10G. Remember, OM1/2 were designed for 10/100 networks, so 1G was already a life extension for that plant. 10G is already outdated as a switch uplink, so at some point in time you have to decide if you got your moneys worth out of the fiber that’s been in the wall for 20+ years and it’s time for a refresh it to something future-ready (singlemode) or if you’re ready to just call the network operationally mature and leave it be. Investing a ton of time into something that’s unlikely to be reliable and scalable long-term is kind of not a great use of anyone’s time. Sure, it’s a few hours now to swap around optics and see what links, and probably good for a laugh. But every time you push a firmware update or replace a switch/optic/patch in that chain you’ll be risking losing the link entirely and once you’ve designed around it being a 10G link it’ll be much harder to adapt back (or it was a complete waste of time).
Well, that sounds great. Let me know when you have a week or two to help run new fiber
We’d definitely prefer single-mode in that space for uplink, but it’s not realistic. The OM2 at 1G uplink (or 10G if we’re lucky) buys us the time we need to design & budget for the future needs as we figure them out.
I know, it’s not what anyone wants to hear but… 1G is gonna be stable and well supported. Putting 10G in on the existing fiber will probably work … until it doesn’t, and then you’re stuck with a crisis. If 1G proves insufficient at least you have a real justification to upgrade the cabling.
I would recommend a splicing kit that you can (probably) find at Lowes or Home Depot. I forget which one I have that I purchased for work (just in case, and to have fun). I think if I recall correctly I use Jonard and have both the Fiber Prep Kit and Fiber Optic Cleaning Kit Plus. As for splicing I will have to look for a good one, the one that I have is very low end and is difficult to use.
I realize this is already resolved, and I’m using a certification kit, but since it is still under $1k I thought I’d post here for anyone else interested. It works for our singlemode and multimode, but I like Karl’s solution better.
I use this light meter/certification kit:
We also got this mandrel kit:
We got this when we bought our fusion splicer so we could verify splices. It has been over a year since I’ve used it, but it did help us identify strands that needed to be re-done.
I still need something to simply shine a light through and verify if I’m looking at the right cable though.
