Ocean Optics S1024DW Install - Manual (Page 45)

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Sampling Optics: ISP-REF Integrating Sphere
The ISP-REF I NTEGRATING S PHERE is an illuminated sampling optic that couples via optical fiber to
Ocean Optics miniature fiber optic spectrometers to measure reflectance (from 360-1000 nm) of solid
objects or emission (from 200-1100 nm) of spectral sources. The ISP-REF Integrating Sphere has a transfer
optic assembly for restricting the fiber viewing angle, a 0.4” aperture sample port, and a built-in light
source (tungsten halogen) with 12-volt DC adapter.
Application Tips
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The Integrating Sphere has two primary functions: 1) to provide even surface illumination for reflectance
measurements, such as determining the color of flat surfaces; and 2) to collect light and funnel it to an
optical fiber for emission experiments, such as measuring the spectral properties of an LED.
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The ISP-REF Integrating Sphere is small and compact -- it's just 2.11” x 2.25” x 3.25” (LWH) and
weighs less than 1 pound -- yet is durable enough for use outside the laboratory. All instrument
electronics -- including the lamp, which can be replaced by simply removing two screws -- are
mounted into the bottom section of the unit.
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The reflectivity value obtained by calculating the difference between the inclusion and exclusion of
specular reflection is a direct measurement of the gloss of the surface. For an excellent explanation of
diffuse and specular reflectance, and of the use of integrating spheres, see “Nonstandard Spectroscopic
Measurements,” Spectroscopy, June 1997.
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The color temperature of the Tungsten Halogen lamp is 3100K.
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The sphere is made from Spectralon, a white diffusing material that provides a highly Lambertian
reflecting surface. A simple switch allows users to manipulate the sampling optic for the inclusion (I)
or exclusion (E) of specular reflectance.
Operation
1. Locate the on/off switch on the front of the lamp. The “1” position is the on position. The “0” position
is the off position. Turn the lamp on.
2. Locate the shutter switch. It is located on the back of the sphere. The “I” (for includes) position means
that the resulting reflection measurement includes both specular and diffuse reflections. The “E” (for
excludes) position means that the resulting reflection measurement excludes specular reflection (the
user will only obtain diffuse reflection measurements). Move the switch to the mode necessary for
your application.
Using the Optical Fiber Ports
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The ISP-REF Integrating Sphere has SMA connectors for two optical fibers. The connector, or port
marked “S” (for sample) is used to couple an optical fiber to the spectrometer to measure the reflection
from a flat surface.
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The second port, marked “R” (for reference), offers two features not available with most other
integrating spheres. One function of the R port is to couple an optical fiber to a second channel in the
spectrometer. This channel can be used to monitor the Integrating Sphere's built-in tungsten halogen
lamp, which provides even surface illumination. The other function of the R port is for the coupling of
an optical fiber to collect light. This may be advantageous for applications involving the collection of a
wide-angle beam of light, especially where the beam is much larger than the size of the entrance optics.