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Uniform sources Diffuse uniform sources


									Uniform sources
Diffuse uniform sources

n   Excellent diffusing properties
n   Range of application: 400 - 1100 nm
n   50 mm diameter output port
n   98% uniformity

These uniform source systems are based on an integrat-
ing sphere. Integrating spheres operate as light collec-
tors. Light may be introduced into the sphere through
a part on the sphere wall or the entire source may be
enclosed within the sphere. The collected light becomes
a very uniform source of illumination.

Light entering an integrating sphere undergoes multi-
ple reflections and is scattered uniformly around the
interior of the sphere. The multiple reflections and
scattering produce uniform, spatially integrated light. A
detector placed at the port in the sphere wall sees an       All sources are available in two versions: with and
output which is completely independent of the angular        without satellite sphere. The source without satellite
properties of the input light. This is a Lambertian source   sphere comes with three internal lamps equally spaced
with a plane port of constant irradiance (measured in        around the exit port. These sources must carefully be
units of watts/cm²).                                         baffled from the exit port to prevent any direct radia-
                                                             tion that might produce a non-uniform output.
                                                             Changing the irradiance of the halogen lamps via the
n   Testing and calibration of electronic imaging device     lamp current will result in color temperature changes.
n   Testing and calibration of detectors                     The uniform source with satellite sphere comes with one
n   Testing of photosensitive materials                      halogen lamp integrated in the satellite sphere. An iris
                                                             diaphragm is installed between the satellite and inte-
System components                                            grating sphere so that irradiance can be varied without
                                                             changing the colour temperature.
Our basic uniform source systems consist of an inte-
grating sphere with BaSO4 coating, internal halogen          The irradiance of the sphere is a function of the watt-
source to emit radiation to the interior of the sphere       age rating of the lamps. We use tungsten halogen
and a regulated power supply to operate the halogen          lamps with our uniform sources. These lamps provide
sources. The uniform source system produces white dif-       a continuous, emission line-free spectrum and they are
fuse light that is exceptionally uniform over the plane of   temporally stable when operated from a constant cur-
the large exit port.                                         rent regulated power supply.

                                                             Power supply

                                                             Since the stability of the light output is an important fac-
                                                             tor we recommend a highly stable DC current source
                                                             for operating the halogen lamps. The uniform source
                                                             uses either one or three 12 Volt lamps up to 50 Watts.
                                                             The three lamps are connected in series, so any power
                                                             supply which handles 3 A and 36 V could be used.

                                                             The power supply we offer is not included in the source
                                                             system. It has to be ordered separately. This power sup-
                                                             ply is a highly regulated constant current or constant
                                                             voltage source. It uses a digital meter to ensure repeat-
                                                             able current or voltage settings. The device is a labora-

1                                         E-mail:
LOT-Oriel Group Europe.                                        For your local contact click at
Uniform sources
Diffuse uniform sources

tory power supply providing 0 - 3 A output current and
0 - 80 V DC output voltage. It has no soft start option,
but by gradually increasing the lamp current to its
operating level proper lamp operation is ensured and
damage to the lamp from in-rush current is prevented.


With all uniform sources we provide a detector port
that is located under the output port of the sphere. As
an option we offer a silicon detector to monitor the
relative actual output level. The lamps and the sphere
may change the output intensity over time and a moni-                     Uniform source with satellite sphere
tor detector indicates the change. If the uniform source
output is to be calibrated then the monitor detector can
often be traceable tied to the output of the source.

Calibrations                                               Ordering information

Most of our diffuse uniform sources are used for rela-     LKH150            Diffuse uniform source,
tive measurements where absolute calibration is not                          sphere diameter: 150 mm
necessary. If absolute data are required, we offer two                       output port: 50 mm
optional system calibrations: Spectral irradiance and                        3 x 5 W halogen lamps
actual uniformity.
Spectral irradiance data read in µW/cm-2/nm at a           LKH200            Diffuse uniform source,
distance of 0,25 m. The data are provided in 5 nm                            sphere diameter: 200 mm
intervals for 280 - 800 nm.                                                  output port: 50 mm
                                                                             3 x 10 W halogen lamps
The actual uniformity calibration measurements are         LKH500            Diffuse uniform source,
performed with an unfiltered photodiode, with an ac-
                                                                             sphere diameter: 500 mm
tive area limited to 1 mm by using a pinhole. The grid
                                                                             output port: 150 mm
spacing of the uniformity map is typically 10 mm, but
may vary for very small or large output ports.                               3 x 30 W halogen lamps
                                                           LKH150S           Diffuse uniform source with satellite
Each calibration comes including a calibration certifi-                      sphere, output port: 50 mm
cate (Swiss Calibration Service, ISO 17025).                                 sphere diameter: 150 mm,
                                                                             satellite sphere diameter: 100 mm
                                                                             30 W halogen lamp

Operating range                  400 - 1100 nm             LSN803            Power supply for halogen lamps,
Uniformity                       98 % (typ.)                                 constant current or voltage,
                                                                             0 - 3 A, 0 - 80 V
Sphere coating                   BaSO4
                                                           LKHD01            Monitor detector (Si diode)
Lamps                            Quartz tungsten halogen
                                                                             including readout (relative units)
Color temperature                2900 K                    K-DSI             Si diode with BNC-connector
Lamp life                        2000 h
Irradiance at the                130 mW/cm²                Calibrations
output port (typ.)                                         LSHK01            Spectral irradiance
(3 x 20 W lamps)
                                                           LSHK02            Uniformity of output plane

2                                      E-mail:
LOT-Oriel Group Europe.                                     For your local contact click at

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