May 25, 2017 | Glossary of Spectroscopy Terms, Spectroscopy, StellarNet Definition
The dark spectrum of a spectrometer is a spectrum taken with no light hitting the detector. It captures the shape of the baseline offset. It can be used to adjust sample spectra for non-uniformities in the detector pixels. The SpectraWiz software is able to do this...
May 25, 2017 | Detectors, Glossary of Spectroscopy Terms
Sometimes thermal fluctuations have enough energy to generate electrons in the same way that photons do. These electrons are not part of the signal, but there is no way to distinguish them from the signal in the detector, so they become a source of noise. The dark...
May 25, 2017 | Glossary of Spectroscopy Terms, Optics, Spectrograph
The f-number, also called the f-stop or the f-ratio, is an optical component’s focal length divided by its diameter: where N is the f-number, ƒ is the focal length, and D is the diameter. Often, this is written as “f/N,” so for N=4, it is written “f/4.” This number...
May 25, 2017 | Detectors, Glossary of Spectroscopy Terms
Popping pixels in spectrometers have a dark current that changes abruptly, likely due to defects in the pixel. It is the most disruptive type of defective pixel because it is unpredictable. There is no way to account for the behavior, so a popping pixel must always be...
May 25, 2017 | Detectors, Glossary of Spectroscopy Terms
Dead pixels in spectrometers have significantly lower responses than nearby pixels. If pixels are merely weak instead of completely dead, they can be accounted for in the system sensitivity curve. However, this will decrease S/N. If this becomes a problem, the dead...
May 25, 2017 | Detectors, Glossary of Spectroscopy Terms
A defective pixel in a spectrometer is a pixel that doesn’t behave as it should to the point of being unusable. This includes dead pixels, hot pixels, and popping pixels. The SpectraWiz software can account for defective pixels and will interpolate a value...