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Chemical Landmark Celebrates pH Meter

Site at California Institute of Technology recognizes Arnold Beckman's invention

April 12, 2004 | A version of this story appeared in Volume 82, Issue 15

Beckman's original pH meter, or "acidimeter," made an appearance at the celebration.
Beckman's original pH meter, or "acidimeter," made an appearance at the celebration.

The American Chemical Society has designated the development of the Beckman pH meter a National Historic Chemical Landmark at California Institute of Technology, Pasadena, where Arnold O. Beckman was a chemistry professor in 1935 at the time of the invention.

Members of the Caltech community, ACS President Charles P. Casey, ACS Board Chair James D. Burke, several other members of the ACS Board of Directors, Beckman's daughter Patricia, and many others gathered at Caltech in late March for a symposium on Beckman's many accomplishments and the dedication of the landmark.

At the dedication, Casey observed that "Arnold Beckman's pH meter changed his career, but more important, it revolutionized chemical instrumentation. That's why I'm proud as president of the American Chemical Society to be with you today to help commemorate that achievement on behalf of ACS and the thousands of chemists who daily rely on the instrumentation that his work spawned."

The plaque that will hang in the courtyard of Caltech's Beckman Institute (one of four buildings on the Caltech campus that Beckman's philanthropy made possible) reads: "Arnold O. Beckman developed the first commercially successful electronic pH meter while a member of the faculty of the California Institute of Technology. This rugged and portable "acidimeter," which had all necessary components housed in a single unit, allowed scientists to measure acidity accurately and rapidly. It immediately met an important need of the California citrus industry: how to measure the pH of lemon juice. The innovative features of the pH meter, including an early use of integrated electronic technology, were the basis for subsequent modern instrumentation developed by Beckman and Beckman Instruments."

Speakers at the afternoon symposium included Stanley Pine, a chemistry professor at California State University, Los Angeles, and a member of the ACS Board; John D. Roberts, emeritus professor of chemistry at Caltech; Gerald Gallwas of the Arnold & Mabel Beckman Foundation; Arnold Thackray, director of the Chemical Heritage Foundation, Philadelphia, and co-author of a biography of Beckman; Harry Gray, chemistry professor at Caltech; and Patricia Beckman.

The speakers reviewed various aspects of Beckman's remarkable career. Beckman, who just celebrated his 104th birthday, was born on April 10, 1900, in Cullom, Ill., a town of about 500 people. He demonstrated an early interest in chemistry, stumbling on J. Dorman Steele's "Fourteen Weeks in Chemistry" at the age of nine. For his 10th birthday, his father gave him a shop in the backyard in which Arnold could conduct experiments. Beckman early demonstrated an entrepreneurial spirit, at age 17 starting a consulting business as an analytical chemist.

After a stint in the Marines just before the end of World War I, Beckman attended the University of Illinois, earning a B.S. degree in chemical engineering and an M.S. degree in physical chemistry. He entered California Institute of Technology to pursue a Ph.D. He left Caltech, moving east to take a job with Western Electric Research Branch (which later became Bell Labs), where he learned about vacuum tubes and was much closer to his future wife, Mabel, whom he had met when he was in the Marines. In 1926, he returned to Caltech to earn his Ph.D., after which he joined the Caltech faculty.

Casey (from left); Gray; Patricia Beckman; Pine; and David Tirrell, chairman of the division of chemistry and chemical engineering at Caltech, help commemorate development of pH meter.
Casey (from left); Gray; Patricia Beckman; Pine; and David Tirrell, chairman of the division of chemistry and chemical engineering at Caltech, help commemorate development of pH meter.

IN THE MID-1930S, Beckman received a request from an old college friend to help him develop a reliable and rapid way to measure the acidity of lemon juice. Thus was born the acidimeter, which was so popular in his friend's lab at the California Fruit Growers Exchange that he soon asked Beckman to build a second unit. Beckman saw the glimmer of a business in the request. He formed National Technical Laboratories to manufacture and distribute the instrument.

According to Gallwas, Beckman sold 87 acidimeters in 1935. In 1936, with the instrument rechristened as the Model F pH meter, he sold 444 units. In 1937, he introduced the Model G pH meter, which sold more than 28,000 units until production ended in the early 1960s.

The pH meter "was the seed that planted the tree of electronics in the field of chemical instrumentation," Gallwas told the symposium. It was the first application of electronics to direct chemical measurement, he said, and it spawned an industry that grew rapidly over the next 20 years with the introduction of instruments such as the DU Spectrophotometer by Beckman Instruments in 1941 for measuring ultraviolet spectra and Varian's first NMR instrument in 1949. Beckman Instruments had sold more than 30,000 DU units by the time it was discontinued in 1976.

Beckman left the Caltech faculty in 1939 to devote himself full time to National Technical Laboratories. Asked once whether he ever regretted giving up his academic career, Beckman said, "I have done more for science in general by making instruments available for thousands to use than what I could do in my own laboratory by myself."

Beckman remained involved with Caltech, however. Roberts told the symposium that, in 1953, Beckman became the first alumnus to be chosen to serve on the Caltech Board of Trustees, and he served as chairman of that board from 1964 through 1974. Of Beckman, Roberts said, "It is quite unlikely that there has ever been a more influential trustee." Roberts also called Beckman a "visionary" philanthropist who has had enormous influence on science during his life.

The Beckman Foundation gave major gifts to the Scripps Clinic and to the University of Illinois in the 1970s. In the 1980s, the Beckmans created five Beckman Institutes in the U.S. devoted to cutting-edge research in various areas of chemistry and the molecular sciences. In addition, Beckman gave $2 million to the Chemical Heritage Foundation for the Beckman Center for the History of Chemistry.

ACS has designated landmarks in the history of chemistry for more than a decade. During the dedication of the landmark at Caltech (the first in Southern California), Casey pointed to two motivations for the landmarks program. "We wanted chemists to recognize and celebrate our profession's rich history," he said. "The nearly 50 landmarks that we have designated demonstrate how chemists have expanded the frontiers of knowledge, developed lifesaving drugs, advanced industry, and developed new products.

"But we also created the landmarks program for another reason. We wanted Americans to learn and appreciate how chemists have improved the quality of our lives."

To the layperson, development of the pH meter may not seem as exciting or important as penicillin or plastic, two other achievements celebrated by landmarks, Casey said. "But nothing could be further from the truth. By making instruments easy to use, Arnold Beckman made it easier for chemists to work on the products that have had a significant impact and benefit to the public--products that improve the quality of modern life."


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