Why multi meter measure the current different with oscilloscope?

Thread Starter

Eric cc

Joined Jul 26, 2020
15
Here I’m used multi meter to measure AC current value different with used current probe on the oscilloscope?
I know the multi meter method is means value, but it couldn’t match with current probe on oscilloscope value.....
Example when I connect with a capacitor element when I increase frequency and multi meter current value increase.
But used current probe always show same value......
 

KeithWalker

Joined Jul 10, 2017
3,092
The input impedance of the two devices is different. When you connect an AC signal to one end of a capacitor and the meter or scope to the other end, you have made a 1st. order high pass filter with the capacitor and measuring device. The the pass frequency will vary with the value of the capacitor and the input impedance of the scope or meter..
Filter.jpg
 

Thread Starter

Eric cc

Joined Jul 26, 2020
15
The input impedance of the two devices is different. When you connect an AC signal to one end of a capacitor and the meter or scope to the other end, you have made a 1st. order high pass filter with the capacitor and measuring device. The the pass frequency will vary with the value of the capacitor and the input impedance of the scope or meter..
View attachment 214522
Got it! Thanks for your help!
 
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