The p H scale has values ranging from 0 (extremely acidic) to 14 (extremely alkaline).
Dedicated March 24, 2004, at Beckman Institute at the California Institute of Technology in Pasadena, California.
Commemorative Booklet (PDF) When Arnold Beckman, a professor of analytical chemistry at the California Institute of Technology, was asked to devise a way to measure acidity in citrus fruit, the resulting “acidometer” revolutionized chemical instrumentation.
The innovative features of the p H meter, including its use of integrated electronic technology and all-in-one design, were the basis for subsequent modern instrumentation developed by Beckman and his company.
The California citrus industry depends on chemistry.
The acidity of the soil and water influences the fruit trees.
Chemists developed the insecticides and fungicides used by growers.Ripeness was determined by the percentage of citric acid in the juice.And finally, large quantities of inferior fruit were processed, by chemical means, into pectin and citric acid.Clearly, the citrus industry needed an accurate gauge of acidity, the problem that sent Glen Joseph to seek the advice of his old friend Arnold Beckman. The most prominent was the colorimetric method familiar to most high school chemistry students.Slips of paper were coated with litmus—a water-soluble powder derived from lichens—then dipped into the solution under examination.If the litmus-treated paper turned red, the solution was acidic; if it turned blue, alkaline.