BLACK-Comet UV-VIS Spectrometer Models
Range 190-900nm
StellarNet's miniature fiber optic spectrometers with concave gratings deliver high performance for spectroscopy applications in the UV-VIS wavelength ranges covering 190-850nm (model C), or optionally 280-900nm (model CXR). The instruments are exceptionally robust with no moving parts, and are packaged in small rugged metal enclosures (2.75 x4 x6 inch) for portable spectroradiometry and lab or process spectroscopy measurements. The BLACK-Comet UV-VIS spectrometers utilize a 40mm diameter concave grating with aberration correction to provide superb spectral imaging. This significantly improves spectral shapes by reducing comma and astigmatism found in plane grating spectrograph designs. The spectrograph architecture does not utilize mirrors, and therefore provides the lowest possible stray light in the UV with additional assistance from the holographic line grating.  The concave grating produces a flat field on the CCD detector creating uniform resolution over the entire range.


Optical Metrology and Colorimetry
BLACK-Comet UV-VIS spectrometer model CXR-25
(-25 denotes slit size) measuring the transmission of a blue plastic film using a SL1 tungsten halogen lamp, TXF-4 transmission fixture, and two F600-VIS-NIR  fiber optic cables and providing colorimetric data in CIELAB color space. Go to the colorimetry page.



Solar Irradiance Monitoring
BLACK-Comet-SR in DSR-CSR-512 system measuring solar irradiance. The dual blaze concave grating allows for superb spectral imaging from 220-1100nm.  


BLACK-Comet Sensitivity
Spectral sensitivity is one of the most important factors in choosing the proper miniature spectrometer. The concave grating optical design allows for high sensitivity and a smooth spectral distribution over the wavelength range as shown in the above spectrum of a Tungsten Halogen lamp.



UV-VIS Absorbance System
StellarNet’s Low Cost UV-VIS Spectrometer system is composed of the BLACK-Comet research grade concave grating spectrometer, a SL5 high stability light source with integrated cuvette holder, and an optical coupling fiber. Above is the absorbance spectrum of various sugars.



LED Metrology
BLACK-Comet concave grating spectrometer for LED measurement capturing spectrum of Nichia White LED (190-850nm or 280-900nm).  SpectraWiz software displays 1931 CIE Chromaticity Diagram with xy chromaticity values within .001 of LED specifications.  Also displayed is LED dominant wavelength, purity value XYZ tri-stimulus values. SpectraWiz software allows the user to save samples, log data, auto-scale, and take dark references.
 

One of the main advantages of the BLACK-Comet is its ability to drastically reduce straylight levels, 0.02% at 435 nm and 0.2% at 200 nm, the lowest values of any field spectrometer. By design, the holographic grating has a smoother surface than the normal ruled gratings used in competing spectrometer models.  Surface roughness is the primary source of grating generated stray light and thus by employing superior grating technology, StellarNet’s Concave Grating Spectrometers are able to drastically reduce the effect. Additionally, grating scatter in the standard Czerny Turner design is collected and focused by the focusing mirror toward the exit port, this does not occur with the BLACK-Comet. When additional optical components like collimating and focusing mirrors are used in instrument design, it is more likely that light may be re-diffracted and scattered. Similarly, due to the spectrometers ability to reduce light scatter, especially high power UV light, the Concave Grating spectrometer provides two to three times enhanced UV sensitivity as compared to plane grating/Czerny Turner optical configurations.

The units are ruggedized.  As shown above the detector is bolted in position and military grade epoxy holds the concave grating in place making the instruments vibration tolerant, durable, and suitable for just about any lab and/or field measurement. A multi-band filter is integrated into the spectrograph to provide order sorting and prevent optical aliasing. The instruments optical input is attached via standard SMA-905 connector, using single strand fiber optic cable with typical silica core diameters of 400um, 600um, 1000um.



Reflectance and Colorimetry
BLACK-Comet measuring the reflectance of roasted peanuts from 280-900nm. CIE lab color data can logged in real time. StellarNet colorimetry systems include a configured spectrometer, light source, reflectance fixture or probe and other sampling accessories.

Optional Configurations
Several units may be daisy chained via a USB-2 hub allowing simple configurations for dual and multi-beam process applications.


Free SpectraWiz Software
The powerful SpectraWiz® 32 bit spectrometer software is provided free of charge with every spectrometer instrument.  This includes drivers and customizable software for operation on Windows.    The SpectraWiz software is considered the "Swiss Army Knife of Spectroscopy and may be used to accurately measure wavelength emissions, reflectance, transmission, absorption, concentrations, and absolute intensities.  In addition to real-time spectroscopy,  SpectraWiz® has built-in applications for SpectroRadiometry, SpectroColorimetry, ChemWiz chemistry lab concentration analyzer, and UV level monitors.



Super Ranges (200-1100nm)
StellarNet has released super range concave grating spectrometers, BLACK-Comet-SR. The grating uses an enhanced Dual Blaze technology to extend the concave grating models range to 1100nm. 
See more at BLACK-Comet-SR  


 
High Resolutions (<0.4nm)
StellarNet has just released high resolution concave grating spectrometers, BLACK-Comet-HR. The new models come in a UV (200-600nm) and VIS (380-750nm) range with resolutions down to 0.4nm. 
See more at BLACK-Comet-HR 

Interface
The system includes a high speed plug & play interface using USB-2 connection.