How to measure the R & c value individually?

Thread Starter

PSIR

Joined Apr 23, 2008
29
Hello everyone

Please take a look at the attached schematic.

There is a 50KHZ AC signal connect to a R-C circuit. Also, There is a instrument amplifier circuit on the right side. The amplifier is able to amplifly the voltage of the R-C circuit. So that I could figure out the Impedance (Z) of the R-C circuit.

According to the formula of electrical Engineering. Z=√The square of R + The square of Xc

While I figure out the value of Z. How to separate the value of R and Xc individually?
If I could get the the value of Xc. Then the value of Capactive can be calculated.

Bset Regard

Thanks!
 

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shteii01

Joined Feb 19, 2010
4,644
Measuring capacitance, C, is hard. I think some of the more expansive multimeter have option to measure it, otherwise you just rely on what is printed on the capacitor.
 

Thread Starter

PSIR

Joined Apr 23, 2008
29
Excuse me. I couldn't posted my schematic on it.
Could any body tell me how do I post my schematic.
Thank you.
 
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Thread Starter

PSIR

Joined Apr 23, 2008
29
Thank you everybody. Finally, I find out the way to up load the schematic file.
Press the "Edit" button then Press the "Go Advanced" button.
So that you can brouse and up load the file what you want to post.
 

shteii01

Joined Feb 19, 2010
4,644
Excuse me. I couldn't posted my schematic on it.
Could any body tell me how do I post my schematic.
Thank you.
Probably the easiest is to take the screen shot of the schematic while it is on the screen by pressing Print Screen key on your keyboard, then open Paint and click paste, save the picture in Paint as a jpeg, upload it here as an attachment when you make a post.
 

t_n_k

Joined Mar 6, 2009
5,455
If you have access to the individual R & C components you need to take one or more additional measurements.

One option is to first measure the resistor voltage, VR.

The current in the circuit is then I=VR/500.

Next, measure the capacitor voltage, Vc.

The capacitive reactance, Xc is then Xc=Vc/I=(500*Vc)/VR

As you indicated, C may then be calculated using Xc and the known source frequency.

There is at least one other possible approach. But your one suggested measurement of the source voltage won't be sufficient.
 
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