DuMond studied at Monrovia High School where his grandparents moved, and then went to the Throop College of Technology (later to become Caltech), earning his bachelor's degree in 1916 with the construction of a calculating machine, a "harmonic analyzer".
He then served in France in the Second battalion, Twenty-ninth Engineers, as a sound ranger, coming under fire but not in direct combat; his commander was Theodore Lyman IV, well-known American physicist.
[4] Starting with his Ph.D. dissertation, DuMond became famous for investigating the line broadening in the Compton effect due to the speed distribution of the electrons in the atom.
With E. Richard Cohen, DuMond published regular review reports on the status of the determination of the fundamental physical constants.
DuMond also developed a gamma-ray spectrometer, finished only after World War II, with which he then pursued nuclear spectroscopy.
[4] During World War II DuMond worked on rocket technology, the construction of an aerial camera, and the demagnetization of ships as a measure against magnetic mines.