On 11 Jun 2011, at 20:11, Matthew Green wrote:
Distilled water *is* virtually non-conductive. It's only the salts and impurities in tap water (and/or river water etc.) that make it moderately conductive.
It's not only the salts. There is some natural ionisation that will result in free H+ and OH- ions. You can't really escape that so even mineral free ultra pure water in a perfectly sealed sterile container (of a material that won't release minerals as the water desperately tries to leach them) will still be *slightly* conductive.
Mineral-free ultrapure water has a resistivity of 18.2 megaohm . cm. I'd call that "pretty damn non-conductive", personally.
Of course, eighteen megaohm water is capable of leaching sodium ions out of glass, so...
DC.
On 12/06/11 12:43, David Crisp wrote:
Mineral-free ultrapure water has a resistivity of 18.2 megaohm . cm. I'd call that "pretty damn non-conductive", personally.
Of course, eighteen megaohm water is capable of leaching sodium ions out of glass, so...
Yeh this is kinda my point...it is possible to make water fairly non conductive (although domestic grade distilled water is unlikely to be at the purity you define) but it is damn near impossible to keep it like that.
I have access to Reverse Osmosis systems that can produce water that achieves something like 0.06 microsiemens/CM of conductivity (which equates roughly to 18meg/CM resistance) but the only way they can do that is by keeping the water in the RO loop in constant cycle through the filters let it stop doing that and it will quickly go up.
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David Crisp -
Wayne Stallwood