 Arnold Orville Beckman

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, later considered to have "revolutionized the study of chemistry and biology".