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Piece wires : Temperature

  1. Sep 29, 2011 #1
    hye... i new user (forumer)... help me....

    1) i have 3- 4 piece wire (copper/ iron)... i dont know AWG for piece wire... no label... the length of wire is 1 foot... how to know / measure / calculate the maximum voltage, maximum current, maximum temperature, thickness, type of metal for piece wire.



    2) temperature relation / propotional - voltage
    - current
    -conductivity
    -resistivity

    *formula / definition
     
  2. jcsd
  3. Sep 29, 2011 #2

    davenn

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    current capability of a wire is primarily proportional to its diameter (thickness) ( and somewhat to the type of wire... copper, aluminium etc) you need to find out what you wire is what its made of, what its size is AWG etc.
    its resistance is also dependant on what its is ... copper etc and thickness
    known cables will have data sheets that will state that info along with its resistance in Ohms / metre(foot) km(mile) etc

    we cant help you without that information

    cheers
    Dave
     
    Last edited: Sep 29, 2011
  4. Sep 29, 2011 #3

    MATLABdude

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    If you have a pair of calipers (or better yet, micrometers), measure the diameter of a STRIPPED portion, and then read it off the chart (this will be a little problematic if the wire is stranded, but not impossibly so):
    http://en.wikipedia.org/wiki/American_wire_gauge

    Note that the information is rule of thumb ONLY. Temperature rating, maximum voltage, and resistance will depend on the insulation used (if any) and the history of the piece (i.e. if it's severely kinked or cut-up in certain areas, the resistance will increase).

    For something where this really matters, get some new pieces of wire. They're pennies per feet.

    EDIT: and pursuant to my point about the 'history' of the piece, this will affect its current-carrying capability.
     
  5. Sep 30, 2011 #4

    vk6kro

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    One way to measure the diameter of a wire is to wind the wire around a cylinder (like an AA battery) so that the turns are right up close to each other.
    Then measure one inch or one centimeter along the coil and count how many turns of wire are in that distance. From this, it is easy to work out the diameter of the wire.

    The most common wire is probably copper. This has an orange-red colour and bends easy.

    Iron wire is attracted to a magnet and it is harder to bend than copper.

    Aluminum wire is silvery-white when cut but it turns to s smoky white as it oxodises.

    Another type you may come across is Nichrome wire. This is very springy and will not wind into a coil easily. It has a very high resistivity and so quite a short piece of this wire has a lot more resistance than a similar piece of copper wire.

    Here is a list of resistivities which will give you a comparison between different materials as conductors.
    http://en.wikipedia.org/wiki/Resistivity

    Also see the wire table given above in a previous post.
    http://en.wikipedia.org/wiki/American_wire_gauge
     
    Last edited: Sep 30, 2011
  6. Oct 2, 2011 #5

    how do know the size of AWG? wire made (material) ???
     
  7. Oct 3, 2011 #6
  8. Oct 3, 2011 #7
    current-carrying capability means ???
     
  9. Oct 3, 2011 #8
  10. Oct 3, 2011 #9

    NascentOxygen

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    magnet?
     
  11. Oct 3, 2011 #10

    NascentOxygen

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    amps
     
  12. Oct 3, 2011 #11

    NascentOxygen

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    yellow=copper
    black = ??????
     
  13. Oct 3, 2011 #12

    sophiecentaur

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    = charred?
     
  14. Oct 3, 2011 #13
    Wires : Resistivity and Conductivity with Temperature

    hye... i new user (forumer)... help me....

    1) i have 3- 4 piece wire (i dont no type of metal piece wire)... i dont know AWG for piece wire... no label... the length of wire is 1 foot... how to know / measure / calculate the maximum voltage, maximum current, maximum temperature, thickness...



    2) temperature relation / propotional with

    - voltage
    - current
    -conductivity
    -resistivity


    *pls give formula / definition....


    http://img192.imageshack.us/img192/7638/dscn5043x.th.jpg [Broken]
    http://img4.imageshack.us/img4/2913/dscn5051f.th.jpg [Broken]
     
    Last edited by a moderator: May 5, 2017
  15. Oct 4, 2011 #14
    Re: Wires : Resistivity and Conductivity with Temperature

    help me....
     
  16. Oct 4, 2011 #15

    berkeman

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    Re: Wires : Resistivity and Conductivity with Temperature

    Welcome to the PF. What is the context of your question? You are trying to figure out the maximum ratings for these wires, given only 1 foot samples? What other information do you have? What is the application for the wire?

    You use standard wire tables and/or the manufacturer's datasheet to figure those things out.

    http://www.powerstream.com/Wire_Size.htm

    .
     
    Last edited by a moderator: May 5, 2017
  17. Oct 5, 2011 #16
    Re: Wires : Resistivity and Conductivity with Temperature


    What other information need i have? What is the application for the wire? pls help me
     
  18. Oct 5, 2011 #17

    NascentOxygen

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    Re: Wires : Resistivity and Conductivity with Temperature

    No one knows. We need you to tell us about it. :smile:

    Did you salvage it from a space vehicle?
     
  19. Oct 5, 2011 #18

    berkeman

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    Re: Wires : Resistivity and Conductivity with Temperature

    I will be patient with you for now.

    Do you have calipers? Do you know how to use them? Calipers will tell you the diameter of the wire.

    What color are the conductors? That will tell you much about the metal used for the wire.

    Why are you given only 1 foot samples of the wire? Is this for schoolwork as quiz?

    Are there any markings on the insulator portions of the wire samples? If so, what did your Google searches reveal about the wire specifications?

    Do not play games with us. We are happy to help if your request is valid.
     
  20. Oct 5, 2011 #19

    berkeman

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    Two threads merged and warning issued to the OP for zero effort.
     
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