SpectroRadiometers
Instruments for LED Measurement
More and more incandescent lights are being replaced by LEDs each day. LEDs have the advantages of increased efficiency, color specificity, size, response time, lifetime, and numerous other factors.  StellarNet's line of low cost miniature radiometers are the perfect tool to analyze LEDs for both irradiant output, color, spectral profiling, and a handful of other useful values. These instruments are NIST calibrated to measure the absolute intensity over the wavelength range in nanometers provided by the selected spectrometer model.  Currently, StellarNet offers LED Radiometer systems in the 200-1700nm range; the table at the bottom of the page outlines various ranges for each StellarNet Spectroradiometer.  The StellarNet BLUE and GREEN-Wave, BLACK-Comet concave grating model, and the RED-Wave-NIR InGaAs model can all be configured for perfect LED measurement.  For a complete LED measurement system, in addition to a StellarNet Spectrometer, a fiber optic cable and an integration sphere are needed for both accurate and precise measurement.


SpectraWiz Software included FREE 
- Absolute intensity measurements watts/m²  
- µm watts/cm²
- PSD
- Lumens/m² -- LUX
- Moles per second -- PAR
- Footcandles /m²
- Radiant Flux (watts) / Luminous Flux (lumens)
- xy Chromaticity, dominant wavelength, purity
- Correlated Color temperature (CCT)
- Set Power Spectral Density (PSD) range

Power and InterFace
Portable spectrometers include a high speed USB-2 interface cable.  All miniature spectrometers with a CCD detector (GREEN-Wave, BLUE-Wave, BLACK-Comet, and new EPP2000 models) are powered by your computer's USB port while spectrometers with InGaAs detectors (RED-Wave) or TEC upgrades require an external 5V supply.  New Big Wave electronics allow plug in play operation through on board memory where all coefficients are automatically loaded into your software.




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.


BLACK-Comet-SR concave grating spectrometer for LED measurements displaying irradiance values in Lumens as well as correlated color temperature (CCT). Choose model C-SR (200-1080nm) or CXR-SR (220-1100nm)

*Note only Concave grating spectrometers can be NIST calibrated for deep UV (IRRADUV-CAL) and VIS (IRRAD-CAL) measurements simultaneously.

BLACK-Comet spectral overlay of UV LEDs tested for our SL1-LED UV kit. In order to choose the best LEDs for fluorescence excitation it is required that the StellarNet R&D test all incoming LEDs for wavelength and absolute intensity as compared to the manufacturers specifications.


BLUE-Wave-VIS model miniature spectrometer can be calibrated for irradiance measurements also.  The spectrometer has a range from 350-1150nm and can be calibrated for irradiance measurements (IRRAD-CAL).  BLUE-Wave spectrometers have the advantage of being smaller and powered by USB; however, lack the benefits of research grade concave grating optics.  Check with a sales representative to determine the best spectrometer for your LED analysis.

















BLACK-Comet spectral overlay of LED tested for optical output power in Watts as a function of varying LED current. Many customers use StellarNet spectrometers to measure output LED intensity as a function of current, temperature, LED optics, and other possible varying parameters in order to completely characterize their systems.

SpectroRadiometer PDF Download

















Why StellarNet SpectroRadiometers?
UV-VIS-NIR Ranges 200-1700nm
Low cost - Ruggedized - high performance
Shock-proof - Permanently aligned
SpectraWiz Software included Free
Battery packs for field measurements
USB-2 interface to all notebook PCs
Measurement accessories for many applications

NIST Calibrations
The factory performs calibrations for the appropriate wavelength range of your spectrometer using NIST traceable calibration lamps (calibration service IRRAD-CAL must be ordered with spectrometer and proper measurement accessories)

Fast delivery: most system can be calibrated and shipped within 1 week after receipt of order

Absolute calibration: accuracy within 10% at detector integration setting used for calibration

Certificate available: documentation with NIST traceable serial numbers.

If the user has an appropriate irradiance calibration source lamp, a field re-calibration can be easily performed using the included SpectraWiz software

Experimental Setup for Laser, Laser Diode, and LED characterization.  Larger Spheres such as IS6 and IS12 can be used in place of low cost IC2.

See more StellarNet Measurement Diagrams!!

StellarNet Integrating Spheres allow collection of light with an 180 field of view.  The IC2 is a 2" internal diameter sphere with 2 SMA connectors for illumination and collection of LED light. The input port is 5/8".  The IS6 and IS12 are 6" and 12" StellarNet integrating spheres with 2.5" input port with internal white coating.  Mounting tripods and other accessories are available for LED measurement.
Integrating Sphere PDF
Integrating Sphere Pricelist

 
SpectraWiz Software allows the users to select the irradiance units. Additionally, scroll down menus allow the user to select their collection accessory in order to calculate radiant and luminous flux.


Above is the spectrum of a 345nm UV LED popular for many biology related fluorescence excitation applications. In order to make LED measurements measurements below 300nm a IRRADUV-CAL is required.

Extended Range Spectroradiometers 
StellarNet also has extended range spectroradiometers available to measure spectral irradiance over a wide range of wavelengths.  The EPP2000-UVN-SR spectroradiometer with CCD detector array covers a range of 200-1100nm.  While the BLACK-Comet-SR super range dual blazed concave grating spectroradiometer offers a range of 200-1080nm or 220-1100nm while retaining all of the characteristics of a concave grating spectrometer. In addition, StellarNet offers a Dual Channel Spectrometer system for spectroradiometry, the Dual DSR (Detector Super Range) combines a CCD and InGaAs detector to cover a wavelength range of 200-1700nm for selected models.

Dual DSR Spectroradiometer- StellarNet Dual DSR system pictured above uses a Y bifurcated fiber (F600-Y-UVSRNIR) to connect a BLACK-Comet-SR spectrometer and a RED-Wave NIR Spectrometer.  The entire system can be radiometrically calibrated over the range 200-1700nm. Above system pictured with Flash Capture Interface (FCI) that allows spectrometer to capture emission from flashing sources such as flashtubes and pulsed solar simulators.