The Development of the Beckman pH Meter March 24, 2004
American Chemical Society SCIENCE
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'The pH meter was just a chance development that I did as a favor for Glen Joseph."
—Arnold 0. Beckman, Interview by Jeffrey L. Sturchio and Arnold Thackray at University of Pennsylvania, 23 July 1985 (Philadelphia: Chemical Heritage Foundation, Oral History Transcript #0014B), p. 13.
Celebrating Chemistry The American Chemical Society designated the development of the Beckman pH meter a National Historic Chemical Landmark on March 24, 2004For additional information see our Web site:
Measuring acidity I n the mid-1930s G l e n Joseph, a chemist at a research laboratory r u n by the California Fruit Growers Exchange, paid a visit to his o l d college friend, A r n o l d Beckman, n o w an assistant professor of chemistry at the California Institute of Technology. Jj T h e Exchange • controlled more than three-quarters of California's citrus output, and it marketed its h i g h quality fruit I under the Sunkist label. Joseph sought Beckman's assistance i n solving a problem: how to get an accurate and rapid measure of the acidity of l e m o n juice. Chemists then measured acidity by several methods. T h e most prominent was the colorimetric method familiar to most h i g h school chemistry students. Litmus-treated paper was dipped i n a solution; i f i t turned red, the solution was acidic; i f i t turned blue, alkaline. A cheap test, but i t is unusable i n the citrus industry since sulfur dioxide, used as a preservative, bleaches out the litmus. Chemists also used electrochemical methods, relying o n the p H scale w h i c h has values ranging from 0 (extremely acidic) to 14 (extremely alkaline). A g a i n , sulfur dioxide caused problems for the measuring devices then available. Joseph had tried using a hydrogen electrode and t h e n a glass one to measure the acidity but his systems were fragile and the signals weak. Beckman suggested using the newly evolving technology of vacuum tube amplification of the weak electrical signal. Joseph left Beckman's office
armed w i t h a sketch showing two vacuum tubes to amplify and then re-amplify the signal. But he soon returned saying the device did not work. Beckman offered to build the instrument himself. He included a newly developed and more rugged glass electrode as the measuring device combined I I w i t h vacuum tube j I amplification. T h i s I I instrument worked so I I well that Joseph soon HHb asked Beckman H f whether he could make a second.
Significance of the pH meter Chemists were just beginning to make use o f electrical instruments i n their research. This was usually done to meet a specific need and typically consisted of l i n k i n g various devices together, w h i c h were then spread out o n the workbench i n a laboratory. Beckman concluded that the vacuum tube amplifier, the measuring electrode, and the data meter should n o t be separate devices but part of an instrument i n w h i c h all components were integrated. I n i t i a l l y called an "acidimeter," this one box u n i t enabled the chemist to purchase the instrument, provide a power source, and immediately begin collecting data. I t was n o longer necessary to assemble the requisite components and the chemist d i d not require m u c h knowledge of the electronics. T h i s basic but innovative approach to instrument design provided the basis for the subsequent development o f modern instrumentation by Beckman and others.
wwwxhemistfy.org/landmarks.
Marketing the pH meter Beckman created N a t i o n a l Technical Laboratories, an outgrowth o f a company w i t h w h i c h he was previously i n v o l v e d , to manufacture and distribute the acidimeter. By September 1935 Beckman had a marketable instrument housed i n a wooden box w i t h a handle and a latch, just i n time for the fall national meeting of the A m e r i c a n Chemical Society i n San Francisco. Beckman took the acidimeter w i t h h i m . " I n particular," he later said, " I asked some o f my former professors, whether, i n their opinion, there would be a market for such an instrument. To put things i n perspective, I should point out that our instrument was priced at $195, and i t would be competing to some extent w i t h litmus paper w h i c h cost only a few cents a vial." Beckman's professors suggested he show the instrument to laboratory apparatus dealers. "Their most optimistic estimate," he learned, "was that 600 m i g h t be sold over a ten-year period before the market would be saturated. N o t a very great sales potential, but I decided to go ahead. After a l l , i t was only a sparetime activity." To help boost sales, the name was changed from "acidimeter" to " p H meter" to emphasize the scale that measures acidity and alkalinity. I n 1936, the first full year o f sales, N T L sold 444 p H meters, w i t h a gross income of $60,000 and a net profit o f $2,358. By 1939, 1,995 p H meters had been sold and the profit for that year was $22,160. Success meant that soon the "Beckman Glass Electrode p H Meter" was featured i n the catalogs of all the major U . S . instrument dealers. Business was so good that i n 1937 N T L introduced the M o d e l G p H meter, eventually selling thousands o f this version.
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Arnold 0. Beckman: Inventor, businessman, philanthropist A r n o l d O . Beckman was born o n A p r i l 10, 1900, i n C u l l o m , Illinois, a t o w n o f about 500 people. A s a nine-year-old, A r n o l d stumbled on J. D o r m a n Steele's Fourteen Weeks in Chemistry. Steele was a teacher who loved developing new scientific lectures and experiments, relating them to household objects and materials. Beckman devoured Steele's lessons, leaving h i m w i t h a life-long love of chemistry. For his t e n t h birthday his father gave A r n o l d a small "shop," an 8-by-10 foot shed that stood behind the family home, i n w h i c h he could conduct his "experiments." For chemicals, A r n o l d scoured his mother's pantry and shopped at the local druggist. W h e n the family moved i n later years, A r n o l d always commandeered laboratory space.
A t age 17 Beckman started a consulting business as an analytical chemist. H e had business cards printed and the l i t t l e laboratory i n his home became the "Bloomington Research Laboratories" w i t h h i m as " C h i e f Scientist." Beckman's consulting work for U n i o n Gas and Electric i n B l o o m i n g t o n , Illinois, was to nun analyses of woods chips soaked i n ferric chloride to determine whether the concentration was h i g h enough to remove the noxious smell that came from b u r n i n g Illinois coal. Before graduating from h i g h school, Beckman aided the A m e r i c a n war effort i n the First W o r l d W a r w h e n he landed a post at the Keystone Steel and I r o n Company i n Pekin, Illinois, analyzing steel samples to
the ultraviolet spectra of compounds. By helping to determine their molecular structure, the D U has assisted i n the development of drugs and foods. For example, during the Second W o r l d War the instrument helped researchers understand the chemical structure of p e n i c i l l i n .
determine their carbon content. After a stint i n the Marines, Beckman attended the University of Illinois, earning a B.S. degree i n chemical engineering and a master's i n physical chemistry. Beckman t h e n entered the new California Institute of Technology i n Pasadena to pursue a Ph.D. but after a year he took a job w i t h Bell Labs i n N e w York, where he learned about vacuum tubes, w h i c h he made good use of ten years later. I n 1926 he returned to graduate school, and, after completing work o n his Ph.D., he joined the Caltech faculty. Beckman easily settled i n t o life as a university professor, c o n t i n u i n g his research and teaching college freshman chemistry. But the commercial success of the p H meter forced Beckman i n 1939 to make a major career decision. For four years he had been r u n n i n g N T L but had only the formal title of vice president. Beckman understood that N T L had grown to the p o i n t where "somebody had to r u n the show full-time. I t was a case o f whether I tried to do that or whether I went out and hired a professional to do i t . " So " w i t h great reluctance" Beckman resigned from Caltech to become president o f N T L . Production of other instruments soon followed. NTL's next major advance was the D U spectrophotometer, w h i c h used some of the technology first applied i n the p H meter. T h e D U spectrophotometer simplified laboratory procedures for making and recording
N T L grew rapidly i n the 1940s. I n 1948 Beckman was able to purchase enough stock to gain c o n t r o l of the company. I n 1950 the company changed its name to Beckman Instruments and two years later i t became a publicly traded corporation. Sale of stock brought an infusion of capital that Beckman Instruments used to buy new, expensive technology and to pursue costly lines of research. Beckman Instruments continued to grow and diversify throughout the last decades o f the t w e n t i e t h century, developing i n t o a leader i n the manufacturing of instruments used i n the daily operations o f medicine and industry and i n research, even space exploration. I n 1997 Beckman Instruments became Beckman Coulter, a m u l t i n a t i o n a l company w i t h offices i n 130 countries and sales i n 2002 i n excess o f two b i l l i o n dollars H a v i n g made a fortune, Beckman decided to give i t away. I n 1977 he and his wife Mabel created the Beckman Foundation w i t h a mission to support basic scientific research w i t h an emphasis o n chemistry. T h e Beckmans initially were the staff and the office was their d i n i n g r o o m table. T h e Beckman Foundation gave substantial gifts to the Scripps C l i n i c and to the University of Illinois. I n the 1980s the Beckmans created five Beckman Institutes i n the U n i t e d States devoted to cutting-edge research i n the molecular sciences. I n addition, Beckman gave two m i l l i o n dollars to the C h e m i c a l Heritage Foundation i n Philadelphia for the Beckman Center for the History o f Chemistry.
T h e A m e r i c a n Chemical Society designated the development of the Beckman p H meter at the California Institute of Technology a National Historic Chemical Landmark o n M a r c h 24, 2004- T h e plaque commemorating the event 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.
About the National Historic Chemical Landmarks Program
American Chemical Society Charles P. Casey, President W i l l i a m F. Carroll, Jr., President-elect Elsa Reichmanis, Immediate Past President James D . Burke, Chair, Board of Directors Organizing Committee Harry Gray, Beckman Institute, California Institute of Technology Jay Labinger, Beckman Institute, California Institute of Technology Stanley Pine, California State University, Los Angeles Southern California Section, American Chemical Society Michael Geis, Chair Thomas LeBon, Past Chair
T h e A m e r i c a n C h e m i c a l Society, the world's largest scientific i more t h a n 159,000 members, has designated landmarks i n the 1 chemistry for more than a decade. T h e process begins at the local level. Members identify milestones i n their cities or regions, document their importance, and nominate them for landmark designation. A n international committee o f chemists, chemical engineers, museum curators, and historians evaluates each n o m i n a t i o n . For more information, please call the Office of Communications at 202-872-6274 or 800-227-5558, e-mail us at
Orange County Section, American Chemical Society Rabin Lai, Chair Richard Deming, Past Chair Institutional Supporters A r n o l d and Mabel Beckman Foundation Beckman Coulter, Inc.
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Acknowledgments: Photo Credits: Pictures of acidimeter and Arnold Beckman holding an acidimeter are courtesy Beckman Coulter, Inc. A l l other photos: Getty Images Other Credits: Chemical Heritage Foundation for the transcripts of Arnold O. Beckman interviews hy Jeffrey L. Sturchio and Arnold Thackray at University of Pennsylvania, 23 A p r i l 1985 and 23 July 1985 (Philadelphia: Chemical Heritage Foundation, Oral HistoryTranscripts #0014A and*0014B). California Institute of Technology, Oral History Project for Arnold O. Beckman. Interview by Mary Terrell, 16 October and 4 December 1978 (California Institute of Technology, Oral History Project, Caltech Archives, 1981). Written by judah Ginsberg The author wishes to thank Maty- Ellen Bowden, Paul Jones, and Frankie Wood-Black of the National Historic Chemical Landmarks Committee for reading the text and correcting inaccuracies. He also wishes to thank Dr. Stanley Pine of the ACS Board of Directors for also reading the text. Needless to say, any errors are the author's alone. © 2004 American Chemical Society
American Chemical Society Committee o n National Historic Chemical Landmarks Paul S. Anderson, Chair, Bristol-Myers Squibb Pharma Company, Retired Mary Ellen Bowden, Chemical Heritage Foundation D. H . Michael Bowen, Consultant Leon Gortler, Brooklyn College A r t h u r Greenberg, University of New Hampshire Janan Hayes, Merced College Seymour Mauskopf, Duke University Paul R. Jones, University of Michigan Heinz Roth, Rutgers University John B. Sharkey, Pace University John K. Smith, Lehigh University Kathryn Steen, Drexel University Isiah Warner, Louisiana State University Edel Wasserman, DuPont Frankie Wood-Black, ConocoPhillips
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