Arnold Orville Beckman was an American chemist, inventor, investor, and philanthropist. While a professor at California Institute of Technology, he founded Beckman Instruments based on his 1934 invention of the pH meter, a device for measuring acidity, later considered to have "revolutionized the study of chemistry and biology". He also developed the DU spectrophotometer, "probably the most important instrument ever developed towards the advancement of bioscience". Beckman funded the first transistor company, thus giving rise to Silicon Valley.  After retirement, he and his wife Mabel (1900-1989) were numbered among the top philanthropists in the United States. Arnold Orville Beckman was born in Cullom, Illinois on April 10, 1900. Beckman Instruments continued to grow in size and also in the range of its products. The company expanded into international markets. The first international subsidiary, Beckman Instruments GmbH, opened in Munich in 1953, as the first postwar U.S. business in Germany. Beckman expanded into new product lines through careful acquisitions. In 1955, he acquired Spinco, a producer of ultracentrifuges. The Beckman Spinco instruments came to dominate the market, proving to be of immense importance in much biological research. There followed a strong development of biological research tools such as amino acid analyzers and sequencers. In addition, the company produced an ever-expanding line of clinical medical instrumentation, such as the oxygen meter and glucose analyzer. He died on May 18, 2004 in La Jolla, San Diego, California, United States.