Abstract: A shutter assembly for use with a spectrometer having at least one source of optical radiation such as at least one laser capable of generating an excitation light beam having an illumination path. The shutter assembly includes a shutter having at least one of (i) at least one calibration material capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer and (ii) a mirror capable of diverting at least one of the illumination path and a collection path relative to a calibration standard capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer. The shutter assembly further includes a mechanism capable of moving the shutter into at least a first position in the path of the light beam and a second position out of the path of the light beam to enable a sample to be analyzed.