COMPARISON OF INTERFEROGRAM NOISES IN THE ULTRAVIOLET AND VISIBLE REGIONS

The sources of noise in ultraviolet (UV), visible, and near-infrared (NIR) interferograms acquired with silicon and germanium diodes as well as photomultiplier tube (PMT) detectors have been investigated. Similar conditions were used with each detector so that noises could be compared with minimal bias. Interferograms were produced from tungsten and deuterium lamps as well as an inductively coupled plasma (ICP). Data were collected from two instruments; a Mattson Sirius 100 UV/Vis spectrometer, and a Chelsea Instruments FT 500. The signal was the average of 4 to 100 interferograms, while the standard deviation of the data was the noise. In addition to the average and the standard deviation, which are the first two moments of the frequency distribution, the third moment (known as skew) was employed to analyze the symmetry of noise distributions.