Collection Sphere Systems

Avian Technologies collection spheres are designed for the general applications of photometry and radiometry. They may be used as cosine collectors, employing either their knife-edged port or another port with a transmissive diffuer as the collection port. With the addition of an internal source or using an external source, they can be used as uniform light sources that give a highly lambertain output.

Collection sphere systems include spun (6" or greater) or machined (diameter 4" or less) aluminum sphere with two ports at 90 degrees from each other along the equator of the sphere (drawing 1), a 1/4-20 mounting boss, and a mounting stand. The port sizes are 25 mm input and 12 mm detector on the 4",6", and 10" spheres and two 12 mm ports on the 2" (50 mm) sphere.

Coating Identifier

B: Avian-B coating: A barium sulfate based coating, similar to Munsell 6080 or Labsphere Spectraflect™. Primarily for laboratory usage. Effective wavelength range 300-1500nm
D: Avian-D Coating: A durable, high reflectance diffuse coating. Excellent for applications where durability or resistance to high humidity is required. Effective range 320- 1360 nm
F: Fluorilon-99W: reflectance material. This is not a coating but rather a machined thermoplastic material. Highly stable, both thermally and has great chemical resistance. Very high reflectance over entire effective range of <250-2500 nm
G: Avian Diffuse Gold Coating: Gold plated over a proprietary multi-layer metallic surface. Most effective in the 1.2-8u range (above 8u, it begins to lose its lambertain qualities) but special treatment can extend the effectiveness to >>25u. Reflectance of >94% over entire range.

See coatings and materials section for full technical information on Avian Technologies coatings and materials.

Reflectance/Transmittance Spheres

Reflectance/Transmittance spheres are designed for the purpose of measuring total hemispherical reflectance or total transmittance of solid materials located on the sphere wall. Typically, a spectrometer is used to illuminate the sample and non-filtered detector is used to collected the integrated flux. By using a 'white' light source and a photopically filter silicon detector, photometric measurements can be accomplished. Finally, if a broadband source is used to illuminate the sample, a dispersive device and a diode- or CCD- array can also provide spectral transmittance or reflectance measurements. The general purpose reflectance/transmittance spheres are configured to accommodate any of these types of measurement. The spheres are also configured to allow double-beam comparison type measurements, which are more accurate than simple 'substitution-sphere' measurements. (ref http://physics.nist.gov/Divisions/Div844/facilities/specphoto/references.html).

Systems include spun or machined aluminum sphere with four ports at 90 degrees from each other along the equator of the sphere (drawing 2), a 1/4-20 mounting boss, and a mounting stand. The ports include two 25 mm reflectance sample/reference ports, a 25 mm entrance/transmittance port, and a 10 mm= detector port. Detector port is screened from reflectance and transmittance port.

Variable Angle Reflectance/Transmittance Sphere

The sphere assembly consists of a 6" sphere with an entrance port, reflectance port at 180 degrees, a center mount for holding either rigid or non-rigid samples (three options on holder), and a detector port configured to view a baffle on the bottom of the sample holder. The center mount is calibrated in one degree increments to allow accurate positioning of the sample relative to the incident beam. The system includes one sphere and one center mount, detector port, reflectance port and port plug. Please specify sphere configuration and sample holder.

Additional center mounts are available for $2500 for Uv-Vis-NIR applications (Avian-D coated) or $3000.00 for mid-IR applications (diffuse gold coated).

(This sphere may also be configured for use with FT-IR spectrometers, using a gold coating)

Variable Angle R/T Sphere

Turbidity/Total Absorbance Center Mount Sphere

The sphere system includes a 6" diameter Avian-D coated sphere with an entrance port, specular subtraction/reflectance port at 180 degrees, a fixed center mount for holding a standard 1 cm path length cuvette at 0 degrees incidence to sample beam, and a detector port configured to view a baffle on the bottom of the sample holder. The sample holder is designed to minimize any absorption loss from scattered radiation.

Turbidity/Total Absorbance (Liquid) Sphere