Dear Tanzila

The impedance detected by the impedance spectroscopy is a summary of the collective works of the conduction and dielectric activities operative under a certain frequency range.

In your case, I assume you are measuring a composite, which is comprised of solid and liquid phases both, therefore I recommend:

1st, find out what mechanisms the impedance spectroscopy is capable of picking up at your defined frequency range,

2nd, find out if these mechanisms were operating in this composite your were measuring (deconvolution),

3rd, identify the nature of each mechanism i.e., bulk conduction? surface resistance? bulk capacitance? etc.

So far, you should be able to know if you are measuring the moisture content alone, or a summary of interconnected mechanisms.

Next, look for literature and equations that calculates these mechanisms (there has to be one).

I suggest starting to measure the capacitance of the deionized water using parallel plates for a try. But you have to make sure the deionized water is the only substance you are measuring (although the filed fringe effect, but the permittivity is less susceptible to the environment in comparison to the conductivity).

hope this helps.

Best

Jiacheng

Dear Jiacheng Zhang ,

Thank you very much for such an excellent explanation.

It would be really nice if you recommend some literature that I can start, thanks in advance.

Best regards,

Tanzila

Dear Tanzila

Thank you for the reply.

I would suggest "2012 Lvovich Impedance Spectroscopy: Applications to Electrochemical and Dielectric Phenomena" and "2008 Martinsen et al. Bioimpedance and Bioelectricity Basics" for a beginners' read for the basic concepts.

and "2005 Barsoukov and Macdonald Impedance Spectroscopy: Theory, Experiment, and Applications" for a more advanced read on the modelling and theories part.

Hope it helps!

Best

Jiacheng

Dear Jiacheng Zhang ,

Thank you again for your assistance and for the provided literature as well.

Best regards,

Tanzila

How can I ascertain that I am detecting (measuring) only the 'moisture content' of the material but not other properties?

You have to get samples of that material when it does not have any water content as well as measure the material at different stages of time. On the other hand, you must then analyze the behavior of bode diagrams, you can check there what is happening in the frequency range. Usually, at high frequency, you can check the bulk properties. And at mid and low frequencies the material behavior.

How can I validate the value of impedance spectroscopy measured experimentally compared with the theory (or the experimental validation of the results through the theoretical analysis)?

Using optimization algorithms to construct the inverse modeling. I recommend you start with Simulink of MatLab which incorporates an optimization library. This tool is easy and intuitive for starter users.

Dear Daniel Andrés Triana Camacho ,

Many thanks for the explanation of the bode curve and also for recommending optimizing the tool.