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# multimeter?

Discussion in 'General Hardware' started by freeboy, Oct 18, 2007.

1. ### freeboy

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ok, so I am clueless regardingthese guys, and I just looked at RS and the digital ones all stated on the packaging will reag up to 10 amps, that hardly seems high enough to test the gpu? Do I not want to see both the volts and the amps?
Help thanks
2. ### Sasqui

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The problem with an in-line amp meter is that the unit has to be able to handle all of the wattage that goes along with it. I suspect anything above 100w is going to be quite expensive. They make "C" clamp ones that don't physically touch the wires, by measuring the inductance caused by the current, but I'm not sure if those work on a DC line. Wish I could be more help.

Edit: The "C" clamp ones only work for AC current.

Edit2: Wattage isn't the issue for an in-line DC amp meter, it is strictly current (the number of electrons moving through the conductor) - Think of a pair of jumper cables for your car, only 12v, but a huge current, hence huge cables.
Last edited: Oct 19, 2007

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what exactly are you planning on measuring? and for which application, what kind of accuracy do you require?
4. ### jamupnorthNew Member

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Yes i could possibly help as well as i use a meter on a daily basis !! ?
5. ### PuMANew Member

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u can allways mesure volts and resistance with it, to get current. heres the formula: I (current) = U(voltage) /(divided by) R(resistance)

thats how we do it in school because like the others said multimeters cant handle big current.

IF u want to change the outcome to P(power) the formula is P= U*I

hope this helps
6. ### freeboy

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ok, I am trying to test my ps to see that , if under load, I am getting the full volts and amps on my gpu cpu etc..
OK re read the threads at ocforum and it seems all you tests is the volts.. Sorry for wastingtime here!

Why do we not need to now if the systems give us the needed amps? Afterall the Gpu's are Amp rated? still alittle clueless! thanks again.
Last edited: Oct 19, 2007
7. ### Sasqui

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Problem there is measuring the resistance. For a solid state system, you can't simlpy hook up a multimeter and measure the resistance.
8. ### Sasqui

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That is probably the most important thing - steady voltage under various loads means more stability. Load is measured in Watts typically, where Watts = Volts X Amperage. When volts remain constant and load varies, that means that amperage varies directly with the load.
freeboy says thanks.
9. ### freeboy

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bingo thanks that is clear.. will look for a bargain ebay mm
10. ### PuMANew Member

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if u hook up ur meter in the 12V line (yellow and black) u can read resistance and volts going thru it and calculate the amperage. @sasqui we use closed circuitry u know
Last edited: Oct 19, 2007