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DI water quality vs. Resistivity

Hello,

I'm looking for a graphical relationship of DI water relative to resistivity. I'm asking for this to show our customer the relationship of resistivity measured in megaohms given a balanced total ionic/cationic condition measured in PPB. I was told the relationship is PPB= 3/megohms, and wondering if a graph like this is available publicly.

Thanks,

Dave Allan White
Disk Drives - Scotts Valley, California, USA
2004

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2004

The relationship of resistivity vs. concentration varies depending upon the ionic species present. This is due to the fact that some ions diffuse faster than others.

Here are a few data points for 25 degree C water.

Resistivity     NaCl      NaOH      HCl in Meg-Ohm-cm
 
1.0             400 ppb   200 ppb   130 ppb
 
5.0              80 ppb    30 ppb     20 ppb

Lyle Kirman
consultant - Cleveland Heights, Ohio

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