The Beckman pH Meter
Arnold Beckman, born 1900, invented the pH meter to help the California citrus industry measure acidity. The device revolutionized scientific instrumentation.
Arnold O. Beckman was born on April 10, 1900, in Cullom, Illinois, a town of about 500 people. Armed with a B.S. degree in chemical engineering and a master’s in physical chemistry, Beckman entered the new California Institute of Technology in Pasadena to pursue a Ph.D.
As a graduate student, Beckman won his first patent, for a signaling device that rang when a car exceeded a certain speed. “You might draw the conclusion from that,” Beckman says, “that my interest in that was derived from the number of tickets I was getting for fast driving.”5 After receiving his Ph.D. in 1928 for research on the photochemical decomposition of hydrazine, Beckman was invited to join the Caltech faculty. Beckman easily settled down to life as a university assistant professor, continuing his photochemical research and teaching freshman chemistry.
In the 1930s, Beckman invented a sensitive and integrated amplifier that measured pH accurately; he also revolutionized instrumentation by building the first chemical instrument in one compact unit that utilized electronic technology and which was portable. This simplified research as a chemist no longer had to assemble various components to test data. Now the chemist could purchase the instrument, provide a power source, and immediately begin collecting data. It was no longer necessary to assemble the requisite components and the chemist did not require much knowledge of the electronics. This rather basic but innovative approach to instrument design provided the basis for the subsequent development of modern instrumentation by Beckman and others.
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Excerpted with permission, National Historic Chemical Landmarks Program