LED Measurement Features 
- Measure LED optical output in Luminous & Radiant Flux, spectral irradiance and LUX, MCD, microwatts/cm2, moles per second, PAR, Footcandles
- Real-time 1931 CIE Chromaticity diagram for xy Chromaticity, Dominant Wavelength, CRI, Purity, and Correlated Color Temperature (CCT)
- LED Testing spectrometers available to cover the 200-2500nm range
- LED Measurement Systems include a miniature spectrometer, a fiber optic cable (or direct attachment), a light collecting accessory/integrating sphere, and a NIST traceable intensity calibration
- New StellarElite System for highest performance
- StellarRad Radiometer App and new interface options via SMART-Control
- LED Measurement Systems Overview
- NIST Calibrations
- Integrating Spheres
- Setup Diagrams
- Application Videos
The typical system consists of a BLUE-Wave VIS spectrometer, F600 fiber optic cable, a 6″ integrating sphere, and a Radiant Flux Calibration for absolute intensity in Watts/nm
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 spectroradiometers are the perfect tool to analyze LEDs for both irradiant output, color, spectral profiling, and a handful of other useful values.
Spectrometers for LED Measurement
These miniature rugged spectrometers are calibrated to test LED optical output in Luminous & Radiant Flux, spectral irradiance, and LUX, microwatts/cm2, moles per second, PAR, Footcandles, CRI & CQS. Currently, StellarNet offers LED measurement systems in the 200-2300nm range. A majority of StellarNet’s spectrometers can be configured for LED measurement including the BLUE-Wave, High Resolution, High Sensitivity SILVER-Nova, and DWARF-Star NIR spectrometer models. The spectrometers can additionally be calibrated with our NIST traceable lamps for absolute intensity to be used to capture LED intensity profiles and shape. Typically an integrating sphere such as the IC2 2″ or IS6 6″ or IS12 12″ integrating sphere is used with a radiant flux calibration (RAD-CAL).
StellarNet LED Testing Solutions – UV-VIS-NIR Ranges 200-2300nm – Low cost – Ruggedized high performance – Shock-proof – Permanently aligned – SpectraWiz Software included Free – Battery packs and handheld option for field measurements – USB-2 interface to all notebook PCs
Visible LED Measurement Spectrometers
The StellarNet miniature spectrometers are fiber optically coupled instruments with a wide selection of models for LED measurements in 200-1150nm wavelength ranges. BLACK-Comet and BLUE-Wave models are both very popular with LED testing
Visible High Resolution (HR) 
and High Sensitivity (SILVER-Nova) Spectrometers
The HR spectrometers have double the resolution over standard models with the same grating. The wavelength range is reduced by the same factor. Resolutions better than 0.1nm can be achieved depending on selected model range, detector, and slit size. The SILVER-Nova and SILVER-Nova-TEC-X2 offer the highest sensitivity with Thermoelectric coolers down 15 & 30 degrees respectively which increase detection capabilities for low light LED measurement.
Near-Infrared LED Test Spectrometers
The DWARF-Star and RED-Wave NIR spectrometers can be spectrally calibrated for NIR LED testing from 900-1700nm. StellarNet offers various optional ranges with increased spectral resolution. Likewise, a NIR can be paired with a visible unit to give you broadband spectral analysis over the 200-1100nm range.
StellarNet low cost LED Measurement Systems reliably test LED optical output in Luminous & Radiant Flux, spectral irradiance and LUX, microwatts/cm2, moles per second, PAR, Footcandles, CRI & CQS
SpectroRadiometer Test Report – Enables customers to prepare and instantly display all of the relevant test data on one sheet making quality control and R&D efforts much more efficient. Instantly, acquire a complete spectrum of your test light source and view its color distribution with an under the curve wavelength color representation.
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StellarNet offers LED testing systems for comparing LED Lumens, CCT, x,y chromaticity, dominant wavelength, and hue for QC/QA in the field such as the StellarRad Handheld Radiometer
Laboratory & Research Quality LED Measurement Systems typically include a BLACK-Comet concave grating spectrometer (with optional TEC), optical fiber, and integrating sphere
NIST Calibrations for LED Testing 
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.
- 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
6″ Integrating Sphere
IS6 is a 6” diameter integrating sphere with a 2.0” input port, internal reflective coating, baffle system, and SMA fiber optic output. StellarNet 6″ integrating spheres are now available with several port accessories such as calibration lamps, caps, SMA-couplers, and reducers.
12″ Integrating Sphere
IS12 For internal LED device mounting. The StellarSphere-IS12 is a 12” diameter integrating sphere featuring a vertical hinge that opens to allow access to the sample stage. The sample stage is equipped with powered device mounting sockets with a variety of detachable socket options. In addition, the StellarSphere-IS12 includes a tungsten halogen lamp and data file for system calibration using the SpectraWiz® radiometer application software. The IS12 option is best for customers trying to capture all of their LEDs emitted light for spectral analysis and total Lumen measurements.
IC2 is a 2” cube with internal integrating sphere. It has 5/8” input port and SMA fiber optic output. Another SMA input can be used for reflectance illumination. Select the IC2-TP miniature tripod for mounting the IC2 for alignment and repeatable measurement.
2″ Integrating Sphere
 Experimental Setup for Laser, Laser Diode, and LED characterization. |
 Setup Diagram for LED Measurement using IS6 6″ integrating sphere. IS6 can be calibrated for incident Spectral Irradiance as well as Total Watt Flux. Optional port hole accessories such as reducers, SMA attachments, & calibration lamps are available |
 Setup Diagram for LED Measurement using IS12 12″ integrating sphere. Devices under test are placed inside the sphere for total flux measurement. Includes aux correction lamp. |
LED Measurement Sample Spectra
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, and auto-scale.
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.
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.
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.
LED Measurement System Options and Pricing
Preconfigured LED Measurement System Options
LED-System
Preconfigured LED Measurement System with IS6 6″ integrating sphere, BLUE-Wave-VIS spectrometer for spectral range 350-1150nm, F600-VISNIR fiber optic cable, & RAD-CAL NIST traceable Radiant Flux calibration in Watts/nm. SpectraWiz Spectroscopy software is included FREE. Preconfigured system also includes a IS-Lamp NIST traceable calibration source for system recalibrations & DUT absorption corrections as well as an RAD-CAL-DOC Certificate of Calibration.
Buy from Online Store$6,700.00
Dual-Radiometer
Dual-Radiometer - This system is a Dual Spectrometer system that includes a BLUE-Wave-UVN spectrometer (250-1100nm) and a DWARF-Star NIR spectrometer (900-1700nm). Both of these spectrometers are coupled via a F600-Y-UVSRNIR fiber optic cable and are attached to a CR2 cosine receptor and CR2-Tp tripod. The entire system is calibrated against NIST traceable source for spectral irradiance measurment in W/m^2 from 250-1700nm (item: IRRADCAL-UVN+ IRRADNIR-CAL). Preconfigured system comes with additional CR2-AP aperture and IRRAD-CAL DOC certificate of calibration.
Buy from Online Store$21,325.00
StellarElite LED-System
StellarElite LED-System with broadband spectral range and deep cooling offers the highest performance when it comes to LED measurement. Systems are calibrated for radiant flux and offer the lowest light detection, accuracy, and repeatability possible with Low Dark Current (LDC) Technology. Great LED research and light color analysis. System with IS6 6″ integrating sphere, HYPER-Nova, F600-VISNIR fiber optic cable, & RAD-CAL NIST traceable Radiant Flux calibration in Watts/nm. StellarPro Spectroscopy software is included FREE. Preconfigured system also includes an IS-Lamp NIST traceable calibration source for system recalibrations & DUT absorption corrections as well as a RAD-CAL-DOC Certificate of Calibration. $31,000.00
Stellar-RAD 
StellarRAD - Handheld SpectroRadiometer for NIST traceable light measurement from 350-1100nm with <1nm spectral resolution. UV and near-infrared ranges are optional. Handheld-Radiometer measures irradiance, illuminance, xy chromaticity, dominant wavelength, CCT, CRI, the complete spectral distribution of all light 350-1100nm, and much more! The handheld system incorporates research-grade BLUE-Wave spectrometer optics. It has an 8″, high performance Android touchscreen interface that’s both ergonomic and user-friendly. System comes with pre-installed StellarRAD Pro software and calibration, direct attach SMA-coupler, CR2 Cosine Receptor, IRRAD-CAL irradiance calibration, and certificate. System charging adapter and USB key included. UV upgrade for 250-1100nm range for $500. $4,200.00
Spectrometer Options for LED Measurement
BLUE-Wave
Visible spectrometer 350-1150nm (UV options available) $3,200.00
BLACK-Comet
Concave Grating spectrometer for UV-VIS. C (190-850nm) or CXR (280-900nm) $3,450.00
BLACK-Comet-SR
Super Range Concave Grating spectrometer for UV-VIS-NIR. C -SR (200-1080nm) or CXR-SR (220-1100nm) $3,950.00
BLACK-Comet TEC Upgrade
Thermo Electric Cooler (TEC) upgrade for low light LED testing to improve measurement sensitivity and detection capability. TEC reducing noise effects over %50 at long exposures and includes a sealed and isolated detector enclosure with specialized heat sink and air flow design for added stability and cool operation. Read More... $1,750.00
SILVER-Nova
High Sensitivity "Super Range" spectrometer for UV-VIS-NIR 200-1100nm. Includes UV detector upgrade, detector lens assembly, composite grating technology, and super cooled TE detector. Interchangeable Slit upgrade – Now available! $1,595 $5,175.00
HYPER-Nova
HYPER-Nova high performance UVIS Spectrometer with Low Dark Current (LDC) technology to provide the lowest background noise possible. Includes front-illuminated, vacuum sealed, CCD detector cooled to -60 deg C. Back illuminated upgrade available for increased quantum efficiency up to 95%! $27,500.00
DWARF-Star
NIR Spectrometer, range 900-1700nm, with cooled 512 element PDA detector $15,500.00
DWARF-Star-1024
NIR Spectrometer, range 1000-1700nm, with cooled 1024 element PDA detector $20,500.00
DSR-CSR-512 BLACK-Comet model C-SR (UV-VIS-NIR, CCD) and DWARF-Star- NIR-512 (InGaAs PDA) for 200-1700nm $19,450.00
DSR-CSR-1024 BLACK-Comet model C-SR (UV-VIS-NIR, CCD) and DWARF-Star-NIR- 1024 (InGaAs PDA) for 200-1700nm $24,450.00
LED Measurement Accessories
F600-VISNIR Armored, 600um diameter single strand, multimode fiber optic cable with black PVC jacket and 2 SMA conectors-2 meter length for wavelength range 400-2200nm. $200.00
F600-UVVis-SR Armored, Solarization Resistant, 600um diameter single strand, multimode fiber optic cable for Deep UV application with black PVC jacket and 2 SMA connectors-2 meters length for wavelengths <400nm. $225.00
CR2 Miniature cosine receptor for UV-VIS–NIR, 1/4 inch diameter with fiber optic cable attachment for irradiance measurements. Calibration performed using NIST traceable lamp operating from 200-1700nm. Buy Online $200.00
CR2-AP Aperture for CR2, allows intensity measurement of sources that are 10 times brighter. $200.00
Col-Tubes Cosine receptor holder with field of view reducing extension tubes. Can be used as a tripod or handheld pointer (gun) for the cosine receptor accessory. Comes with a set of 3 field of view reducing “collimating tubes” with 10, 20, and 30 deg FOV. Custom lengths also available. Buy Online $250.00
CRLENS Cosine receptor lens assembly reduces the field of view from 180 degrees to a small spot. Adjustable focus allows variable distance from target surface $295.00
CR2-RA is a 90° right-angle Cosine Receptor cube $475.00
CR2-OR Miniature cosine receptor for UV-VIS–NIR1/4 inch diameter with fiber optic cable attachment for irradiance measurements with O-Ring seal for underwater applications $275.00
CR2-TP miniature Tri-Pod stand for CR2 with 3 folding legs, setup any orientation, case included. $75.00
IC2 Integrating Cube (Light Sphere), 2 inch cube with 5/8 inch input port, 1 SMA fiber output, Barium Sulfate white coating. Buy Online $600.00
IC2-TP miniature Tri-Pod stand for IC2 with 3 folding legs, setup any orientation, case included $75.00
IS6 is a 6” integrating sphere with a 2.0” input port, 1 SMA fiber optic output, and internal white coating. Buy Online $2,050.00
IS-Lamp is a Calibrated Miniature 10 Watt fiber optic VIS-NIR light source for the IS6 mounted on a 2″ port cap, 400-1050nm, NIST traceable. Includes lamp with data file used to calibrate the system for total flux measurements in watts/nm and lumens/nm. $650.00
IS-SMA is a SMA connector mounted on a 2″ port cap with internal white coating. Allows direct connect of SMA terminating optical fibers to integrating sphere $175.00
IS-RED is a 2″ port cap with reduced sized 1″ diameter aperture with internal white coating $175.00
IS12 is a 12” integrating sphere that allows for internal mounting of devices for light measurement such as discrete LEDs, arrays, and bulbs. The sphere opens for simpleaccess to mounting devices. IS12 Sphere includes lamp with data file used to calibrate the system for total flux measurements in watts/nm and lumens/nm. $4,125.00
FCI Flash Capture Interface for spectrometer trigger $375.00
LED Measurement Calibration Services
IRRAD-CAL Irradiance calibration service in Watts/m^2 using NIST traceable lamp that covers 300-1100nm. Requires fiber optic cable and cosine receptor attachment such as CR2, IC2, IS4, IS6, IS8, or IS20. $350.00
IRRADUV-CAL Irradiance calibration service for 200-400nm. Requires UV-SR fiber optic cable and CR2 cosine receptor $350.00
IRRADNIR-CAL SpectroRadiometric Calibration service for NIR range 900–1700nm $350.00
RAD-CAL Radiant power calibration in Watts/nm 300-1100nm or 900-1700 nm also for LED Lumens/nm $350.00
RAD-CAL-SR Radiance calibration in Watts/sr/m^2 for Candela (Cd/m^2/nm) – requires CR2-LENS $350.00
IRRAD-CAL-Low Description: Low-light level calibration to measure 10x lower intensity emissions. Please specify wavelength range needed. Certification document not included. Please Note: Calibration replacement file costs $125.00.
$350.00
RAD-CAL-SR-Low Radiance calibration in Watts/sr/m^2 for low light Candela (Cd/m^2/nm) – requires CR2-LENS. Low light calibration performed with Lens assembly only $350.00
IRRAD-CAL-Fast Expedited Calibration Service guaranteed <1.5 weeks. Contact for availability $550.00
IRRAD-CAL-DOC Optional Calibration Certificate with details of calibration instrumentation and date and signature of calibration technician $175.00
RE-CAL Annual NIST traceable calibration service, instrument inspection, and x-axis realignment. Choose one from any of our offered calibration services including IRRAD-CAL for spectral irradiance, RAD-CAL-SR for spectral radiance, RAD-FLUX for radiant flux, and low light calibration options. Each additional calibration is $350 with an option for a calibration certificate. $700.00
IRRAD-CAL-Replacement File Copy of original calibration file supplied in electronic format by e-mail and/or replacement USB key. $150.00
*Note: actual spectrometer range can be smaller than range described for radiometric calibration
*Please contact a StellarNet sales representative about more spectrometer configurations
*Annual recalibration discounts and recalibration packages available
Preconfigured LED System Specifications
Preconfigured System StellarElite LED Measurement Standard StellarNet LED Measurement
Spectrometer Model: HYPER-Nova BLUE-Wave
Wavelength Range: 350-1100nm 350-1150nm (Optional UV @ 250nm)
Slit Size: Interchangeable 25, 50, 100, 200 50um
Spectral Resolution: <1nm (with 50um slit) <1nm
Measurement Range: ~0.0005-400k Lux/ 0.0025-1600W/m^2 ~ 0.05-400k Lux/ 0.25-1600W/m^2
System Dynamic Range:
(min to max signal)75db 68dB
Receptor Type: 6" Integrating Sphere (12" Optional) 6" Integrating Sphere
(12" Optional)
Integration time: 10ms to 8 minutes 10ms to 60s
Wavelength Accuracy: <0.25nm <0.25nm
Power Accuracy: +/- 3%, NIST Calibrated +/- 5%, NIST Calibrated
Color Accuracy: +/-0.001 (reference standard lamp) +/-0.001 (reference standard lamp)
Color Repeatability:
xy
CRI
CCT"+/- 4.97E-05
+/- 0.009
+/- 0.2+/- 0.000328
+/- 0.02
+/- 1.5
Power Repeatability:
lumen/mcd/mwatt
bright light0.01% 0.05%
Power Repeatability:
lumen/mcd/mwatt
low light @ 1 minute exposure1% 5%
Software included: StellarPro, Python SDK StellarPro, SpectraWiz, & All Customizable SDK
Included Spectroscopy Software
Our new StellarPro Software for Windows/Mac/Linux is a combination of our popular SpectraWiz software with advanced tools and an application module style interface, be prepared to have your mind blown. Built-in modules for Radiometry, Colorimetry, Chemical Absorption/Kinetics, Chemometrics, Spectral ID, Raman, Multichannel, Haze, & Thin-Film.
Free SpectraWiz Software
The powerful SpectraWiz® spectrometer software is provided free of charge with every spectrometer instrument. This includes drivers and customizable software for 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. Download SpectraWiz Software FREE
SpectraWiz Software Suite for LED Measurements
- Absolute intensity measurements Watts/m2
- µm watts/cm2
- PSD
- Lumens/m2 — LUX
- Moles per second — PAR
- Footcandles /m2
- Radiant Flux (watts) / Luminous Flux (lumens)
- CIELAB xy Chromaticity, dominant wavelength, purity
- Correlated Color temperature (CCT)
- Set Power Spectral Density (PSD) range
StellarRAD for iPhone and Andriod – Light Spectral Analysis App
The StellarRAD App for all WiFi-enabled StellarNet spectrometers (zAP2 WiFi upgrade) makes real-time light measurement quick and easy. Acquire full spectrum analysis of LEDs, lamps, lasers, solar or grow lights, and just about any type of luminaire from ultra-violet through the visible and near-infrared!
This intuitive app lets users control their spectrometer and capture basic and more advanced light measurement parameters such as spectral irradiance and lumens. Colorimetric analysis such as CRI (color rendering index), CCT (correlated color temperature), xy chromaticity, and much more are included. Easily save and export your data and full spectral graph as an .IRR text data file, screenshot, and/or PDF report with all parameters listed.
SpectraWiz MobileTM for Linux/RasPi
The SpectraWiz MobileTM for Linux/RasPi is designed to run directly on the SMART-Control spectrometer interfaces or can be packaged for your your requirements. Using the local access point or WiFi you can easily log in and run applications for General Spectroscopy, Radiometry, Colorimetry, and Concentration analysis.
The easy to use applications are written in python and provided free with purchase of a SMART-Control spectrometer upgrade. Source codes can be purchased separately and can be further customized to suite each user’s requirements. OEM customers can add their logos or additional computations and industrial customers can set their spectrometer and stream their data to PLCs or other process monitoring platforms. SMART-Control devices support RS232, 4-20mA Analog, 26 pin digital I/O, Ethernet, I2C and other options available upon request.
Interface Options
Standard Interface
The system includes a high speed plug & play interface using USB-2 connection.
zAP2 WiFi Upgrade
The zAP2 WiFi upgrade enables WiFi access to any spectrometer. Now use our new StellarRAD App on your iPhone or Android device. zAP2 WiFi upgrade can be added to all new and some old spectrometers in the field. Once added, the spectrometer runs as normal receiving power from the computer’s USB; if 5VDC power is connected directly to the BLUE-Wave, the zAP2 WiFi powers up and you can connect your device. Also, the zAP2 enables USB over IP and you can run SpectraWiz wirelessly on your Windows computer. $600.00
SMART-Control Interface Upgrade
The SMART-Control device offers communication flexibility and application specific customization for any StellarNet spectrometer. This add-on interface includes an integrated CPU with 1GB RAM and many communication protocols such as RS232, SPI, 4-20mA Analog for PLCs, Digital I/O, Ethernet, Wifi and many other options. The SMART-Control allows customers to move their spectrometers into process or OEM environments and stream their selected real world data.
Technical Information Request
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