Dr. Charles William Beckett, 75, a retired assistant chief of the heat division of the National Bureau of Standards, where he did research on chemical thermodynamics at high temperatures, died of emphysema Feb. 3 at Suburban Hospital.

Dr. Beckett's work had applications in rocketry and other technology involving very high temperatures. He was known as a pioneer in developing rapid methods of measuring the properties of materials at great heat.

In 1967, he received the Gold Medal of the Commerce Department for his work. Other honors included the Ludwig Mond Prize of the Institution of Mechanical Engineers and the Huffman Memorial Award from the U.S. Calorimetry Conference.

Dr. Beckett, who lived in Bethesda, was born in Humble, Tex. He received bachelor's and doctorate degrees in chemistry from the University of California at Berkeley. He moved to the Washington area in 1950 to begin his career at the National Bureau of Standards and retired in 1976.

He was a member of the International Union of Pure and Applied Chemistry and chaired a committee he formed in that organization on plasma chemistry.

His wife, Helen Jaeger Beckett, died in 1972.

Survivors include a daughter, Charlotte Beckett Canales of Silver Spring; three stepchildren, Tricia McCort of Elkridge, Md., Michael Speiser of Frederick, Md., and Helena Jones of Eau Claire, Wis., a brother, James Victor of Palo Cedro, Calif.; a sister, Josephine McCoullogh of Wheelock, Tex., and six grandchildren.