zero conductivity (absolutely zero efficiency) fluid recommendation

[mbyka]

hi guys i am looking ,
zero conductivity (absolutely zero efficiency) fluid recommendation for electrical conductivity.
I will immerse the + and - ends of a DC power supply in a 10 liter container with this liquid
and
I will set up DC48V and 100A DC power supply and no current should flow even at 1ma or 1

cheap and if possible, very easily accessible fluid (it can be a transparent oil type)

i want to use for cooling system buit in exchanger and radiators

The right liquid should not become conductive again due to contact with metal,
while passing through metal heat exchanger, metal (copper or aluminum) radiators and plastic pipes (total length of the pipe is 5m) at the time of circulation!.

Or maybe I should ask like this;
Are there special filters to prevent this circulating liquid from gaining conductivity again? Where can I get these filters?

I am grateful to everyone who wants to share their knowledge and experience on the subject.

[Manuel]

No ION in liquid let you have no current transportation mechanism.

So, demineralised water.

Take care,

X!

[Vineyards]

The conductivity unit is Siemens/cm and it is reciprocal to electrical resistivity (1/resistivity).

As mentioned earlier, if there are no ions in water no electric current can flow. That being said, there is a limit to how pure demineralized water can be. A quick browse on the Internet suggests  0.055 µS/cm at 25C is the maximum you can get. This then can be converted as roughly 19 Mega Ohms. However, this will gradually change as water is exposed to the air. CO2 concentration in the air will gradually bring its conductivity to the ~0.8-1.5 mS/cm range. This is caused by an increase in the ionic strength of water due to increased H- ion level which will also bring down the pH level of the solution. So the resulting conductivity will now be many times greater. (1M Ohm resistivity).


Meanwhile, milliamp is actually not a small enough unit to conclude there is no conductivity. There are pico and Femto. Anything beyond Femto currently exceeds the capabilities of electrical measurement devices or techniques accessible to us mortals.

Conductivity is also affected by temperature. Each salt solution has a different temperature coefficient. In the case of NaCl, it is roughly 2.2% per C.

[Sideshow Bob]

It is a product named Novec from 3M, Made for what you want. I do not know more about it other from what I have read though
https://www.3m.com/3M/en_US/novec-us/applications/immersion-cooling-of-power-electronics/
https://www.3m.com/3M/en_US/particles/all-articles/article-detail/~/how-to-cool-computers-3m-novec-liquid-immersion-cooling/?storyid=40f78f75-eda6-4e67-aecc-3d0c026cfe44

[LithiumOverdosE]

That being said, there is a limit to how pure demineralized water can be. A quick browse on the Internet suggests  0.055 µS/cm at 25C is the maximum you can get. This then can be converted as roughly 19 Mega Ohms. However, this will gradually change as water is exposed to the air. CO2 concentration in the air will gradually bring its conductivity to the ~0.8-1.5 mS/cm range. This is caused by an increase in the ionic strength of water due to increased H- ion level which will also bring down the pH level of the solution. So the resulting conductivity will now be many times greater. (1M Ohm resistivity).

I was just about to suggest using double-distilled water (ddH2O) which has much lower contaminants content than simply demineralized and even deionized (DIW) water.
However I didn't take into account exposure to the gasses in the atmosphere.

High purity transformer oil might do the trick but on the other hand it is hygroscopic.
Not really a problem because one can boil it to expel the moisture.

[Sideshow Bob]

I first saw the use of Novec from 3M in a Der8auer video on Youtube (Yes it is spelled correct der8auer) But it is also some other videos on Youtube about Novec.
https://www.youtube.com/results?search_query=3M+Novec+

[solutions]

Mineral oil should work. It won't corrode the metal parts.

Just ensure it has no modifiers or additives....there are sometimes metal compounds.

I would say baby oil, but in some countries that could result in infants in olive presses to achieve the end goal 😬

[Manuel]

3M™ NOVEC™ 649 ENGINEERED FLUID it's perfect since also no O2 in ( ..... no corrosion process ).

used as dielectric > 40kV
used to cool down electronic assembly
used to recover heat
 
check it...

https://multimedia.3m.com/mws/media/569865O/3m-novec-engineered-fluid-649.pdf

take care,

X!