Is it easy to use Ti instead of steel, for a presumptively lower Rct value(s) ?

Thanks you. But I wanna use Steel coupons only. So is there any alternative???

Convert the Fe to Fe2O3, still if you find high charge transfer resistance, further convert Fe2O3 to Fe3O4, then you can record AC Impedance response in kerosene medium.

Normally to test mild steel they will bring passivation in the metal.

Eventhough it is passivatated, becoz of kerosence high Rct values are coming

If your test conditions (simulation of environment) permits, you can add a pinch of NaCl to promote conductivity. 

Generally I am doing my experiments in 20 ppm chloride + Kerosene environment. Eventhough, chloride is present (from HCl) conductivity is not increasing. 

Say, if possible, what is your exp. set up for conductivity.

My experiment is impedance studies of mild steel in 20 ppm chloride(40 ml distilled water) + kerosene mixture.(460 ml) 

Thank you very much. Also, say, if possible, what is the instrumentation (for conductivity measurement)?  Which company?

Ad for example any organic salt for example dodecyloaminium chloride but first check solubility. :) 

How do you avoid kerosene's (possible?) gas phase e.g. (micro, nano) bubbles ?

In crude oil pipelines, along with crude some amount water with chloride is present. Because of that chloride n water corrosion is happening to the pipelines. So this is my study. Anyway I have to do electrochemical studies in this particular environment.

If is easy then bubble your solution with Argon (or Nitrogen) to remove-minimize other (possible) gas phase, before the measurement. If your (measurement) set up is now able to measure well then you might have a good starting point for other (minimum) modifications in your project.

Thank You Dr. Ioannis Samaras

Dear Chaitanya,

you still did not answer Ioannis question, what instrument (make/company) you are using. I do not believe that it is impossible to measure the impedance of your system (the typical low frequency limits (Solartron,Novocontrol, Imry, etc..) is around 10^14 Ohm !! It is also the fact of the matter that in general, the response from interfaces (steel coupons - what are they ?) and bulk (kerosene) are separated in frequency. Did you indetify what is what ? Do a geometrical scale experiment, where you increase the "thickness" of your kerosene layer by factor of 2. Then the bulk  impedance should increase by a factor of two, while the measured capacitance (the real part) should decrease by a factor of two. If no changes in the real part of impedance and the real part of capacitance are observed, then you are measuring the interface response and I guess that that is what you are after ?!

I hope this will help yuo on the way

With best regards

Petr

 Dear Dr. Petr Viscor,

Thank you very much for your keen suggestions. My instrument is very old. It is Zahner iM6e, German Make. My instruments low frequency segments are not working properly. May be this is one of the reason. My environment is Kerosene and water mixture. The suggestions given by you are meant to me a lot. I will go through the suggestions that you made and will update you.

Thank you once again.

Dear Chaitanya,

I use the same (Zahner iM6e, taken in 1995) and, ... I survive, till today.

yes sir.... I also very comfortable with it in my University. Whereas, here in my R&D it is not working properly.

Dear Chaitanya,

try to use Frequency in the initial range (1.0MHz to 0.51Hz) where noise is lower for Zahner iM6e.

Ok... I will try

Thank You