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METHOD PROCEDURE
3. Follow the line up, until it intersects the fluoride curve corresponding to the
fluoride concentration in the sample.
4. From the intersection of the fluoride and aluminum line, follow the line to the
left until it intersects the y-axis. This point corresponds to the corrected aluminum
concentration in the sample.
E.g. Aluminum reading on meter 0.40 ppm and fluoride content in sample 0.50 ppm,
corrected aluminum concentration in sample is 0.75 ppm.