An X-Ray Photoelectron Spectrometer for Chemical Analysis.

Abstract The word "spectrum” may be most generally defined as a correlation between kind and number. In the physical sciences the term "kind" is generally understood as denoting "energy" or "mass” while "number" invariably means "intensity”. In the general field of physical spectrology it will be noted that intensity is a quantity which usually may be measured directly, while energy and mass are measured indirectly. Thus, in the study of electromagnetic radiation spectra it is the wavelength which is usually measured rather than the quantum energy. There is, of course, a simple relationship between the energy and the wavelength, E= hc*/ λ.