TH is a general light source for visible and NIR range spectroscopic applications. Tungsten-Halogen lamps are near blackbody sources of light with fused silica envelopes around the tungsten filaments and a small quantity of an active halogen gas such as Bromine. The TH light source provides very stable and smooth spectral output so it can be applied to spectroscopic measurements (transmittance/reflectance/absorption) and color measurements. The dominant spectrum is from 300nm to 2.6µm depending on the color temperature of each lamp (due to the deep absorption band and the natural transmittance of the fused silica envelopes, the IR range is limited to 2.6µm).
D2 is a general light source for UV range spectroscopic applications. D2 lamps produce intense ultraviolet radiation by maintaining a stable electric arc in a deuterium atmosphere. The spectral power distribution of this radiation has a continuous range that extends from 160 to 400 nm (D2 spectrum). This continuous and stable characteristic of the arc makes deuterium lamps the most useful source of UV for analytical instruments, including spectrophotometers, liquid chromatography detectors, medical analyzers, pollution analyzers, colorimeters, and densitometers. Because of the stability and reproducibility of deuterium lamps, they are suitable as secondary calibration standards in the ultraviolet region.
Xe is a general light source for UV, visible and NIR range spectroscopic applications. The spectrum curve in visible range is relatively flat compared to other light sources. The 175W Xe light source (Xe spectrum) is a compact and light weight high intensity light source. It is especially suitable as a light source for spectroscopy, microscopy, optical scanning, and industrial uses, as well as for use with SP's popular Digikröm monochromators and spectrographs. According to the bulb type, it can cover ~185-2200nm (dominantly, ~250-1100nm), ~320-2200nm (dominantly, ~320nm-1100nm) and ~320-700nm.