Portable element analysis unit

A field portable X-ray fluorescent spectrometer is described, including a multichannel analyzer and a plurality of interchangeable sensor heads. Each sensor head includes a shutter which, when open, permits one of several radiation sources to irradiate the material to be analyzed. The returned radiation is detected by a corresponding detector which provides corresponding data in response. When the shutter is open, the multichannel analyzer utilizes the detector data to accumulate an energy spectrum of the material being analyzed, and displays the spectrum on a display screen. A cursor control allows the operator to move a cursor along the displayed spectrum. The symbol of the element having its major spectral peak at the position identified by the cursor, is automatically displayed on another display screen. Memory is provided for storing a number of reference spectra which may be displayed on the first screen along with the acquired spectrum for comparison purposes. The memory also stores previously acquired spectra for later analyses. To permit quantitative chemical analysis of materials in the field, the analyzer also includes other operational features such as normalization, window control and ratio and concentration determination