The result of your conversion between microgram/liter and grain/gallon [US] appears here
To convert between Microgram/liter and Grain/gallon [US] you have to do the following:
First divide 1.0E-9/0.001 / ((0.45359237/16)*(192/175)/480)/0.0037854118 = 0.00005842
Then multiply the amount of Microgram/liter you want to convert to Grain/gallon [US], use the chart below to guide you.
Symbol: µg/l
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Symbol: gr/gal
No description