The ISP-REF Integrating Sphere is designed for applications requiring even surface illumination for reflectance measurements -- such as in determining the color of flat surfaces.

The ISP-REF is 1.5" in diameter and features a transfer optic assembly for restricting the fiber viewing angle, a 0.4" aperture sample port and a built-in tungsten-halogen light source with 12 VDC adapter. The sphere is coated with 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.

The ISP-REF Integrating Sphere is available for only $1825. Replacement bulbs (item ISP-REF-B) for the illumination source are available for $50.

The ISP-REF Integrating Sphere is small and compact -- measuring just 54 mm x 57 mm x 83 mm (LWH) and weighing 865 g -- yet it is durable enough for use outside the laboratory. All instrument electronics -- including the lamp, which can be replaced simply by removing two screws -- are mounted into the bottom section of the unit.

User's Tip

The reflectivity value obtained by calculating the difference between the inclusion and exclusion of specular reflection is a direct measurement of surface gloss.

The ISP-REF Integrating Sphere features SMA 905 Connectors for two optical fibers. The connector, or port, marked "S" (for sample) is used to couple an optical fiber to the spectrometer for the measurement of reflection from a flat surface. The second port -- marked "R" (for reference) -- offers features unavailable with most other integrating spheres.

For example, 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 a reference the integrating sphere's built-in tungsten halogen lamp, which provides even surface illumination. The R port can also be used for coupling 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. (The FOIS-1 Fiber Optic Integrating Sphere also serves this purpose.)

Specifications