Frequency Response Analyser or Impedance Spectroscopy

[Wayne]

Hi

I am looking for a Labview program to allow the freq. response of say a
tuned circuit.
I will be using a GPIB Function Gen. From 1Hz to 10MHz and measuring the
peak-peak value across a shunt resistor that is in series with the tuned
circuit.
Thus as the frequency increases then the tuned circuit will respond
accordingly. If we take samples every 100Hz then we can produce a spectra
of the tune circuit.
I actually going to use this for measuring the char. of an electrochemical
cell.

Any Suggestions



Wayne

[Anonymous]

Wayne,

Looks like a sweep sine analysis should give you a good idea about the
frequency response. Make sure that you measure the input and output
signals of the circuit; this way you can just compeir RMS values and
get the frequency response.

Another method that you may want to look into is a broad band
frequency response. Basically you send white noise to the circuit;
then you acquire the input noise and the output noise; the you
calculate the FFTs of this data and compair it; after some averaging
you get the frequency response graph of your device. LabVIEW has a VI
called Frequency Response Function that does a large part of the job;
together with the "Frequency Analysis of a Filted Design.vi" example
you can get a good idea on how to perform this test.

I ho
pe this helps.

Regards,

Juan Carlos
N.I.

[Wayne]

Thanks Carlos

The latter method I did not think of but will try it.

Cheers


Wayne

"JuanCarlos" wrote in message
news:506500000005000000A45C0100-1075935269000@exchange.ni.com...
> Wayne,
>
> Looks like a sweep sine analysis should give you a good idea about the
> frequency response. Make sure that you measure the input and output
> signals of the circuit; this way you can just compeir RMS values and
> get the frequency response.
>
> Another method that you may want to look into is a broad band
> frequency response. Basically you send white noise to the circuit;
> then you acquire the input noise and the output noise; the you
> calculate the FFTs of this data and compair it; after some averaging
> you get the frequency response graph of your dev
ice. LabVIEW has a VI
> called Frequency Response Function that does a large part of the job;
> together with the "Frequency Analysis of a Filted Design.vi" example
> you can get a good idea on how to perform this test.
>
> I hope this helps.
>
> Regards,
>
> Juan Carlos
> N.I.