Back to Forum
Post a Response
    Replies Archived Message

    Posted by Peter Wright on January 8, 2004, 12:51 am, in reply to "Re: Rover 45 diesel Y plate battery going flat"

    I agree with Tony.

    To Nigel; the clamps use the magnetic field, emanating from the conductor during current flow, for measurement so the insulation will not effect them. The problem is the size of the conductor in relation to the size of the jaws in the current clamp. The smaller the conductor in relation to the jaw size, the more inaccurate the reading and this inaccuracy is multiplied by small current flows which is what we are looking for.
    As an example, one of our exercises is for the students to measure the A/C compressor clutch current - specs are 3.0 to 3.5A. When using a normal quality current clamp, it fails (shows around 2.9A). When using a multimeter it passes (around 3.15A)

    You can buy low current clamps and you will notice that the jaws are considerably smaller and therefore they are more accurate on small conductors with small current flow. However, the size of the drain we are looking for, I would use a digital multimeter as Tony suggested.

    Cheers

    Peter Wright

    Message Thread:


Copyright © uk autotalk