Solar Spectrum Uniform Light Sources

Labsphere XTH-1200 Solar Spectrum Uniform Light Source

A uniform source with a D65 solar spectral power distribution

Further Information	Technical Drawings
» XTH-1200 & XTH-2000 Datasheet	» XTH-1200/2000 Drawing

The Labsphere XTH-1200 and XTH-2000 are uniform light sources which seamlessly combine the output of an incandescent lamp with a xenon discharge source to boost the sphere's output in the blue part of the spectrum in order to match the spectral power of the ASTM D65 standard daylight illuminant. The XTH sources are well suited to calibrating space-based imaging systems and for testing the quantum efficiency of photovoltaic devices.

The XTH-1200 & XTH-2000 approximate the spectral radiance Albedo1 (defined by ERIM) by combining xenon and tungsten halogen sources within a 12 or 20 inch integrating sphere. The systems are also designed to duplicate the spectral shape of solar radiation while also approximating any spectrum with colour temperatures in the range from 3000 to 6000 Kelvin. The XTH-1200 provides a 4 inch lit area, while the exit port on the XTH-2000 is 8 inches. The luminance and colour temperature of the XTH sources are set by varying the amount of light that is coupled into the sphere from the external halogen and xenon lamps. Motorised variable attenuators are used for this purpose.

Two monitoring systems are deployed on the XTH sources. A photometer monitors the source luminance while a CCD spectroradiometer is used to record the spectral irradiance of the sphere in the range from 350-1050nm for any lamp configuration or variable attenuator position. Software for sphere and spectrometer control is included.

Specifications & System Configurations

Main Specifications	XTH-1200C	XTH-2000C
Sphere Type	US-120-SF	US-200-SF
Integrating Sphere Dia. (inches)	12	20
Exit Port Dia. (inches)	4	8
Luminance (cd/m²)	0 - 20,500 @ 6,000 K	0 - 7,000 @ 6,000 K
Uniformity (%)	98	98
Colour Temperature (Kelvin)	Adjustable 3,000 - 6,000	Adjustable 3,000 - 6,000
System Configuration
External Lamps
EHLS-200-150 (150W tungsten halogen)	x 1	x 1
EXLS-200-175 (175W xenon)	x 1	-
EXLS-200-300 (300W xenon)	-	x 1
Power Supplies
LPS-150-0625 (150W)	x 1	x 1
Xenon lamps have an integrated power supply	-	-
Variable Attenuator	2 x VA-200-SC	2 x VA-200-SC
Variable Attenuator Controller	2 x MC-1000	2 x MC-1000
Monitor Detector	SDA-050-P-RTA-CX (photopic response)
Monitor Photometer / System Controller	SC-6000
Monitor Spectroradiometer	USB2000+ (350-1050nm)
Software	Labsphere USS uniform source control software
	Ocean Optics SpectraSuite spectrometer software
Standard Calibrations	Luminance (cd/m²)
	Spectral irradiance (W/m².nm, 350-1050nm)
Optional Calibrations	Illuminance (lux)
	Integrated radiance (W/sr)
	Luminance mapping