Impedance Analyzer

[Gerald_Topalli]

Hello, 

I am trying to build an impedance analyzer in labview for frequencies 10mHz to 100kHz. 
Is this possible by using myDaq? 

Thank you for your time, 
Gerald

[JÞB]

Note this thread was split from;

A thread that started a decade ago 

@Gerald

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[Henrik_Volkers]

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@Gerald_Topalli wrote:

Hello, 

I am trying to build an impedance analyzer in labview for frequencies 10mHz to 100kHz. 
Is this possible by using myDaq? 

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Peeking into the spec tells me max samplerate (ADC&DAC) is 200 kHz, so 100 kHz isn't possible without tricks 😉

In it's simplest way you need a known inpedance in serie with your DUT. (Or a set of known to extend your range and resolution)

Apply a sine exitation (maybe buffered), measure both voltages, do sine fits to get mag and phase ... 

Measure some pF at 10 mHz and 10 V amplitude will get tricky too 😄  ...not much electrons to move 😉

Parasitic impdedances from your fixure and voltage measurement will add too ... 

another way: known and unknown element in series between both analog outputs, use the AOs to excite while keeping the joint at zero.

[Gerald_Topalli]

Hello Henrik, 

Thank you very much for your reply. 
I think I understand how the overall structure should work but I am failing to understand at the moment the meanings of the number of samples and rate and their correlation to the 200kS/s (I am rather new on labview and mydaq). As for supplying 100kHz signal, I thought of applying a square signal and create a bandpass filter to only take the 100kHz harmonic, and then multiplying it by some factor. But reading your message also lets me know that I cannot read a 100kHz signal (because the current will be in that range). So I think I have to find a solution to that also. 

Bests, 
Gerald