Hi Mahsa, normally you want to calibrate your electrode system (@ 10 kHz or so) in an electrolyte with a known conductivity (like 0.01 M KOH which has 1278 µS/cm @ 20°C). There you get a cell constant, which can be used to convert your measured impedance @ 10 kHz on unknown systems.

Best regards, Andreas

Hi Andreas

Thanks for your response. The problem is we are working with an organic gel that we are limited in introducing gel in aqueous electrolyte solutions. What we did was that we just measured the impedance while gel was not in any electrolyte solution. Is there any way that we can measure the conductivity of organic gel either as solid or in organic solution without using aqueous electrolyte solutions?

Thanks

Sure, you can measure impedance of the gel independently of any electrolyte. Typically you'd use a 4 point probe to measure that. Depending on the geometry of the setup you may be looking at impedance through or across the surface of the gel/solid. If you don't have a reference material to use to establish this easily you will need to figure out the whole of the normalized impedance (which is just inverse conductivity).

Impedance will normalize by Ohms*cm^2/cm so you need to know the area through which the current is traveling (and that area needs to have normalized current density across it) and then the distance between the two points where the voltage--and hence impedance--is measured. If you don't have a reference material, that first aspect makes doing this kind of a pain. You need a setup that will ensure normalized current density across the whole path area. If you know the path area and length, then you can normalize Z to Ohm*cm and take the inverse to get S/cm.

Thats correct, without a refernce system you need to know your cell constant ( area and distance of electrodes)

Dear Mahsa Abbaszadeh,

could you show, please, a photo[1] of your (electrodes[2 -) probe?

1. Also, It would be helpful, if you could show a 2nd photo with your

gel coated on the probe, e.g. the InterDigitated platinum electrodes.

2. 4 point electrodes (probe) VdP-method to measure the conductivity. https://en.wikipedia.org/wiki/Van_der_Pauw_method