Arnold Orville Beckman, American chemist, inventor, and philanthropist (d. 2004)

Arnold Orville Beckman (April 10, 1900 – May 18, 2004) 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 (and alkalinity), 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 Shockley Semiconductor Laboratory, the first silicon transistor company in California, 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.