Detectors - StellarNet, Inc.

What is a Hot Pixel?

May 23, 2017 | Detectors, Glossary of Spectroscopy Terms

A hot pixel has a higher than average dark current. This can be accounted for in the dark spectrum or by cooling. However, if the dark current is too large, the pixel might saturate prematurely. If that is the case, the pixel can be considered defective and...

What is Pixel Resolution?

May 23, 2017 | Detectors, Glossary of Spectroscopy Terms, Spectrograph

Pixel resolution is simply the dimensions of the detector in pixels. For StellarNet detectors, the CCD is 2048 x 1 pixels and the PDAs are 512 x 1 or 1024 x 1 pixels. Notice that they are all linear detectors. Computer monitors and TVs are also described according to...

What is a spectrometer Linearity?

Apr 25, 2017 | Detectors, Glossary of Spectroscopy Terms

Linearity is a property where the pixels in a detector have a linear relationship between the number of electrons generated and the voltage produced. It only happens for a certain range in the number of electrons. Above it, the pixel saturates and the voltage stops...

What is a Saturation?

Apr 25, 2017 | Detectors, Glossary of Spectroscopy Terms

Saturation is what happens when a pixel generates too many electrons. After a pixel exceeds its pixel well depth, the signal from the pixel stops increasing with more photons. The stored electrons can even start “leaking” into neighboring pixels and distorting the...

What is a Pixel?

Apr 25, 2017 | Detectors, Glossary of Spectroscopy Terms

A pixel, also called an element in PDAs, is an individual semiconductor in a larger array of many semiconductors used in electronic detectors such as CCDs and PDAs. When using detectors for 2D imaging, these semiconductors correspond directly to the pixels in the...

What is a Photodiode?

Apr 25, 2017 | Detectors, Glossary of Spectroscopy Terms

A photodiode is a device that turns photons into current. When a photon strikes a photodiode, it generates an electron. The electron then gets swept away down an electronic circuit. This generates a current which can be measured.