10A.3 Basic Components of Spectroscopic Instruments The spectroscopic techniques in Table 10.1 and Table 10.2 use instruments that share several common basic components, including a source of energy, a means for isolating a narrow range of wavelengths, a detector for measuring the signal, and a signal processor that displays the signal in a form convenient for the analyst. In this section we introduce these basic components. Specific instrument designs are considered in later sections.