Discussion in 'General Electronics Chat' started by phuzionz, Mar 30, 2009.

  1. phuzionz

    Thread Starter Active Member

    Dec 5, 2008
    Hi forummembers,

    i was thinking about how to measure the quality of a electronic wire.
    When a wire undergoes stress during lifetime, it can be damaged and it's possible that the electrical characteristics are changing.
    For example, the wire lies in a oven on 140 degrees during 1000 hours.
    how can i measure the quality of the cable after the test?
  2. cumesoftware

    Senior Member

    Apr 27, 2007
    Electrical resistance per length and ampacity (the capacity of carrying current) would be two good ways for measuring the quality of a cable. You should focus mainly on resistance. If the cable has more than one conductor, you can also measure the conductivity of the insulators between conductors (conductor to conductor) per length.
  3. phuzionz

    Thread Starter Active Member

    Dec 5, 2008
    Thank you for the answer.

    Can i measure the resistance with a ordinary multimeter? Is it accurate enough?

    How can i measure the conductivity, that is a very general term for me.
  4. gotumal

    Active Member

    Mar 24, 2008
    I don't think that with some instrument we could measure the "quality" of wire over it's life time.
    There are specified environmental tests to test the effect of temperature, humidity, corrosion (class of protection), turn radius (minimum radius with wich a cable could be bent without damaging the sheath or core), no. twists (no. of times the wire can be bend with turn radius before it breaks) etc. The effect could be a change in resistance, dielectric strength, turn radius, no. of twist etc. So the quality doesn't mean resistance alone.

    Refer the environmental standards for wires and cable assemblies from Lap or Molex
  5. phuzionz

    Thread Starter Active Member

    Dec 5, 2008
    I saw on the farnell websiteb that it is possible to buy a conductivity meter. But what is he just doing?
  6. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    A Fluke 87 Has nanoSiemens for a conductivity range past 40MOhms.

    I believe most damage to wire would involve losss of insulation/shorts, rather than electrical properties.