Hacker News Reader

Comment by davidhyde | Hacker News Reader

Distilled water does not conduct electricity. It is the dissolved ions in the water that allow electricity to conduct. You may be able to clean the PI to such a level that nothing dissolves into the water when it is submerged.

https://techiescientist.com/does-distilled-water-conduct-ele...

View on HN

Even ultrapure water conducts electricity. It says right here [1] that its resistivity is 1.82×10^9 Ohm * m.

This is a pet peeve of mine. We get told of conductors and insulators in school, but it doesn't work like that. Pretty much everything except a perfect vacuum conducts electricity. It's just that some materials conduct electricity so poorly that it can be rounded off to 0 in most circumstances, but there can still be measurable current flow.

[1] https://en.wikipedia.org/wiki/Electrical_resistivity_and_con...

Ok, sure but 1.8 billion ohms puts you in insulator territory. Same ballpark as rubber or glass.

So no, you shouldn't really consider distilled water a conductor.

It's actually quite conductive when you'd try to exploit it's breakdown strength as coolant and insulation for high voltage power electronics.

A perfect vacuum conducts electricity as well: https://en.wikipedia.org/wiki/Schwinger_limit

Getting it that clean is hard. There's stuff like residual flux under the ball grid arrays and other surface mount components.

AFAIK electrolysis will force you to utilize a scrubbing system anyways once you've got current passing through the water. But getting conductivity acceptably low is much less demanding than getting it this extremely low. E.g. some CO2 lasers are cooled with purified water to limit the current through it.

That's true. The YAG laser I used in grad school had the flash lamp inside a water jacket, and the light went through the water.

I mean things like CW CO2 tubes running in the kV range and being immersed in water with exposed electrodes.

Reply on news.ycombinator.com