The calibration lamp module can be used to obtain wavelength calibration arc spectra. This is shown schematically in Figure 31. The module contains Xenon and Argon lamps as well as an incandescent lamp which may be useful for flatfielding. A rotary mirror is used to select one of the three lamps and a flip mirror is placed in the telescope beam to direct the lamp light to the detector.
Figure 31: Schematic of the IMB calibration lamp module looking from
above and showing the flip mirror, the lamp select mirror, and the
xenon and argon lamps.