Multimeter Vs. Twisted Pair

[rpearson]

Seekinng options for doing tests such as length,ohm,resistence,etc,with handheld multimeter.Thanks.

 

[franklin97355]

Fluke and Wavetek have devices for this. A standard VOM won't be of much help.

 

[fonedude]

Try the OmniScanner or Omniscanner2 manufactured by Fluke(formerly Microtest). Great machine, a little pricey though.

 

[cmario]

Cablepuller:

Sounds like you want to do tests without buying any hi tech meters! It's possible, but very labor intensive! To make it easier, you would have to have two people, one at each end of cable, with walkie talkies. Short one pair at a time and measure the resistance. Compare each pair and ohm readings should be about the same. If you have a cable chart, you can calculate ohms/ft. and determine the length. But of course it can't tell you any transmission characteristics! Those hi tech meters don't sound so bad now, huh?

cmario

 

[rpearson]

Well I knew it could be done with a multimeter,but didnt realize it required that many steps...thanks all.

 

[c0i0nes]

Worse than that, Cablepuller, the most basic requirement is the wiremap, i.e that the correct wire goes to the correct connection on the plug/socket at both ends, i.e 1 to 1, 2 to 2, 3 to 3, etc. up, to 8, and you could only do that with a multimeter by comparing each of the eight wires to an external reference, such as an earth connection. Straightforward resistance measurements would be of little use, you would need to know the impedence measurements at 10MHz,100MHz, and nowadays at 1GHz too. You'd have to work out the length of the wire from the time it takes to pass a signal from one end to the other - any clue how to do that with a VOM? Then there's attenuation, Near End Crosstalk...
The answer is, I am afraid, no easy way.

 

[UIHC]

I currently use a Fluke now. I do not like near as much as the Pentascanner that I used up north. for testing impedence, opens, length I would use the Pentascanner with the transceiver. It is very easy to do, the whole unit only costs around $3,500.00 or so.

http://www.bizrate.com/marketplace/...x__cat_id--467,prod_id--5206116,format--.html

Richard Butler MCP A+
Network/Communications Engineer III
UIHC Telecommunication Services

Even Pigs can fly with the proper amount of thrust!

http://groups.msn.com/RichardsBruce/2000camaross.msnw

 

[josepablomir]

December 2002 issue of Poptronics magazine includes the part I of a very simple cable tester (open, short, reverse pairs). January 2003 issue will conclude it.
The design is based on the PICmicro family, and I'm sure the total cost of building this project shouldn't be higher than $200 including all components and extras.
If you only need basic cable testing and don't have a some thousand dollars budget maybe this device could be of your interest.
New in the microcontroller field? Don't worry, there are lots of books and starting kits that could help you with the first steps.

Regards,
_________________
Jose P. Mir
jpm@jpmir.net

 

[daronwilson]

That is definately an interesting article, nice project.

If you are looking for a ready made project today though, and one with input protection (the kit connects the wires directly to the I/O pins on the microprocessor), you may want to consider the options at the following link:

http://www.wisecomponents.com/storecatalog/utptester.htm

Here you can choose from simple wiremap tools starting at $60 up to complex test equipment. This page is a pretty good representation of what is readily available.

Good Luck! It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com