Oscope setting

Discussion in 'General Electronics Chat' started by superway, Jun 29, 2011.

  1. superway

    Thread Starter Active Member

    Oct 19, 2009

    I want to measure 70Aac load from a unit under test on Oscope. I have a curent probe Fluke, the rating is 10mv/A for 200A and 100mv/A for 20A, the other end is BNC connector that connects to Chanel on Scope. I tried to set 20V/div on my scope, but it stops at 10V/div. My scope doesn't have option to change x10 or x100 setting. when I measured the current, it goes all the way up so i could not measure the current. Do I have to change different current probe? Is there any way to measure the AC current on scope without using current probe ( or using standard probe)?

    Thanks in advanced

  2. someonesdad

    Senior Member

    Jul 7, 2009
    You say you're trying to measure a 70 A AC current. Your transducer outputs 0.01 V/A, so your signal should be 0.7 volts. What's the problem? Your scope should measure this easily.
  3. tom66

    Senior Member

    May 9, 2009
    Make sure you connect the grounds of your probe and the scope. I've had odd 80V spikes appear before doing this.
  4. #12


    Nov 30, 2010
    One way to use a 'scope to measure current is to put a resistor in series with the current and measure voltage across the resistor, but I must agree that you are describing conditions that are not likely with the scopes we are familiar with. I answer with some doubt about why you are having a problem.