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Converting part per million to ounces per gallon for a dilute chromate seal

I am doing analysis on a Dilute Chromate Seal for a chromic anodize line, my question is I am checking for Hexavalent chrome on this bath but the procedure I have gives me the results in PPM, now if I have a low result I need to add chromic acid to raise it into spec, the chromic I am using is in flake form (solid) so I need to figure out how many ounces per gallon of chromic to raise to the hex chrome 1 PPM, any input would be greatly appreciated.

Stephen Clark
quality control tech. - Weatherford, Texas, US
December 12, 2008

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First of three simultaneous responses --

one ppm is the same as 1 milligram per liter.

Don Baudrand
Consultant - Poulsbo, Washington
(Don is co-author of "Plating on Plastics" [on Amazon or AbeBooks affil links]
           and "Plating ABS Plastics" [on Amazon or eBay or AbeBooks affil links])
December 17, 2008

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Second of three simultaneous responses --

Stephen

Try entering the phrase "convert PPM to oz/gal" in a search engine. It should take you where you want to be.

Willie Alexander
- Colorado Springs, Colorado
December 17, 2008

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Third of three simultaneous responses --

1 ppm = 1 mg/L.

1000 mg/L = 1 gm/L

gm/L divided by 7.5 = av oz per gallon

0.001 grams divided by 7.5 = 0.00013333333 av oz/gal

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

December 17, 2008