Cleber Borges

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  1. Hello @attila, Good Morning, I imagined that using the reference resistors (such as the impedance analyzer extension board) could have been used the I-V method, since it would be easy to calculate the current value (I) ... But, given your explanation, I understand that the AI tool still uses the same method: Transfer Function Analysis (or the same as FRA - Frequency Response Analysis) ... [I needed this information to report] Thank you very much for your response and dedicated attention to this issue. Cleber Borges
  2. Hello @attila Thank you for your consideration and for your response. My question is more about the theory itself. Since I have the Magnitude and Phase experimental measure, the rest of the properties are reasonably easy to calculate by a CAD (algebra software) My concern is to know what are the real limitations involved in measuring when I ask about fundamental differences.
  3. Hello everyone, Reading about the EIS area - Electrochemcical Impedance Spectroscopy - I found that currently commercial potentiostats implement Impedance analysis by the method: FRA - Frequency Response Analyzer, also referred to as Transfer Function Analysis. As far as I understand, this method would be the same as the one implemented by the Network Analyzer tool in AD2 (am I right? 🙂 ), since in its description it consists of: "The Network Analyzer is used to analyze transfer functions (the ratio between an output function and an input function)" If I can have the Impedance Analysis (measurement) implemented by the two tools: (i) Network Analyzer and (ii) Impedance Analyzer; with differences observed between the two tools, for example, in the frequency range: Network Analyzer = 2 mHz up to 10 MHz - and no "open" and "short" compensation option Impedance Analyzer = 200 uHz up to 25 MHz - and with "open" and "short" compensation option Which made me have the following doubts: [1] - What is the fundamental difference between them? [2] - I saw that the Impedance Analyzer tool forces the current calculation while the Network Analyzer emphasizes the voltage attenuation. But what is the implication of this? In the literature, I saw the defense of the FRA method based on measurement accuracy. The source signal is multiplied by the attenuated signal and the result is given from this combination. [3] - Does the Network Analyzer tool algorithm follow this form? [4] - In the WaveForm examples, there is the use of reference resistors for use of the Network Analyzer tool. Is it mandatory to use them or can you close the circuit by connecting to Ground-GND? Many thanks for your attention and patience! These details may be basic to those trained in electronics, but it is difficult to find them in referrals from other areas. And it certainly makes all the difference trying to do the measurement correctly. Once again: thank you! Cleber Borges
  4. Hi @attila, Is there any future revision possibilities for the IA-adapter to be able to contemplate these three electrodes? Since minimizing the connectors, wires, welding ... And always using the same precision resistors greatly improve the accuracy of measurements. It would be an interesting platform for use in electrochemistry with the use of 3 electrodes. thanks Cleber Borges ps.: (here in Brazil I never found resistor 0.1% to buy) :-(
  5. Hi @attila, Good Morning! As far as I understand, this implementation: W1-C1P-DUT-C1N-C2-R-GND was tailor-made for the example I mentioned! Thank you very much because it will be much easier to do chemistry tests. In general, in Chemistry, the frequencies of ~ 1kHz - 100kHz are more usual and values of ~ nanofarad Thanks :-) Cleber Borges
  6. Many thanks @attila, But if you say you tested in the differential configuration, I will not try to do it because I do not have much experience or material for these tests. And logically for the use of 3 electrodes I would necessarily need to use differential mode. In any case, it would be very useful for electrochemistry if it worked.
  7. Dear all, Good afternoon! In electrochemistry, a system of 3 electrodes is used to: 1 - measure the Potential (V) between the Working Electrode (WE) and the Reference Electrode (RE) 2 - measure the current (i) between the Working Electrode (WE) and the Counter-Electrode (CE) The RE is constructed so that no electric current must flow between WE and RE. My question is: If I use the schematic of figure B, the tool: Impedance Analyzer, implemented in Waveform, will it use the potential difference of the channels of the Scope1 (+) port and the (-) port? My goal is to characterize the Impedance in WE (Working Electrode) as a Randle Cell (Figure C) without the interference of the other two electrodes - RE and CE. (Figure (A) illustrates the electrochemical cell in use in conventional potentiostats for voltammetric study) Thanks in advance for your attention and comments. Thank you very much Cleber Borges
  8. Hello I'm trying to use the Impedance tool via script but I could not adjust the WaveGen parameters. Is there any tutorial for AD2 in this part of the script? In addition, is there any technical limitation for the amplitude to be exactly zero? Because, for me ( voltammetric cyclic ), does it make any sense to just adjust the Offset and not have the Amplitude; Thank you very much Cleber Borges Image of WaveForm Debugger below //// script /// // Step 01: Calculate the Impedance (Z) (fixed frequency) versus the Voltage variation (range) // Step 02: Calculate the current (Ic) // Step 03: Make a XY plot ( current as function of voltage ) ///////////////////////////////////////////////////////////////////// if( !('Impedance1' in this) ) throw "Please open the Impedance tool"; ///////////////////////////////////////////////////////////////////// // Configurations: Impedance1.Frequency.value = 100 ///////////////////////////////////////////////////////////////////// var Z = [] // vector of Impedance values var Ic = [] // vector of Current values nScan = 100 // points numbers in scan stepU = 10 // step (increment) in U for( var i = 1; i < nScan; i++ ){ U = i * stepU Impedance1.WaveGen.Offset.value = 0 Impedance1.WaveGen.Amplitude.value = U Z = Impedance1.Traces.Ref.getData("Impedance") print("impedance value: "+Z ); Ic = U / Z print("current value: "+Ic ); } ////////////// error: //////////// Error in line: 4 TypeError: Result of expression 'Impedance1.WaveGen' [undefined] is not an object. Error in line: 10 TypeError: Result of expression 'Impedance1.WaveGen' [undefined] is not an object.
  9. Exactly! Excuse me ... I did not pay attention to the export. Is that I was imagining this data in the "Notes" tab ... Excuse me. Thank you very much. Cleber Borges
  10. Using the Impedance Analyzer tool (Waveform 3.8.18), I have seen that it now has a "Notes" tab (View -> Notes) which is very useful ... Thank you for implementing this feature in the software! :-) Now, by abusing a little more, I have a suggestion or request so that, if possible, implement a functionality (of a button, a function) that captures all values of the parameters set to print in this "Notes" tab ... It's just a suggestion! :-) Thank you for your attention. Cleber Borges
  11. Hello @attila, I'm seeing the updates now ... Thank you very much for the new limits and Nyquist Plot. :-) the item: 1) - Wavegen, Network/Impedance Analyzer: external Amplification option Will it be possible to have tips in the future? the item: 2) Sound Card device CPU usage: I'm still looking for where to see this feature! ... :-) The AWG for my sound card worked fine in the line-in (Scope) thank you so much Cleber Borges
  12. Ok, I got it. :-) @attila Very cool. A voltage divider is a really a simple solution. Some more questions: 1 - For amplification would a very well specified OpAmp be needed? Is transistor amplification n 2 - Some details of the sound card appear in the image: is 32bits or float more advantageous? 3 - In "WaveForms - Network" there is option of Nyquist Plot as visualization mode. Is it possible to access this view also in "Impedance"? Many thanks Cleber Borges
  13. in addition: In the Biology and Food Sciences, the 1MHz to 20MHz region is widely used for viable cell counts - VCC [2] [2] - Electrical impedance spectroscopy (EIS) for biological analysis and food characterization: a review J. Sens. Sens. Syst., 6, 303-325, 2017