Avian Optics and
Spectroscopy Group

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Distribution		 Services &
Support		 Meet the People

Murakami Color Research Laboratory
GP-200 Goniophotometer

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Goniophotometric measurements are those where the incident and detection angles are varied, and typically many incident/detection pairs are measured to quantify some aspect of the appearance of a material or object. The GP-200 accomplishes these measurements by automatic and independent change of incident and receiving angles. This multi-angle measurement provides analysis of the intensity distribution of reflected or transmitted light as shown in the diagrams below. By providing this accurate intensity distribution the GP-200 is an indispensable instrument for the quantification of appearance. Included software performs complete instrument control as well as the datas processing and visualization of the results.
Several optional sample stands are available, including automatic rotation, automatic translation, manual flop adjustment, and a specially designed holder for hair measurements.
The beams from the light source are converged onto the pin hole through the condenser lens, and converted into parallel beams through the collimator lens. These beams reach the specimen plane through the beam iris. The beams reflected or transmitted from the specimen plane are fed to the receptor via a telescope lens and a receiving iris. Thus, the reflectance, transmittance and diffuse reflectance of the specimen can be obtained by measuring the light intensity.
Applications
  • Analysis of the properties of the transmitted light for plastics or glass
  • Measurement of the roughness of metals or painted plane by optical stylus
  • Analysis of the optical properties of materials with magnetic paints
  • Analysis of the properties of paper
  • Analysis of the optical properties of hair
  • Investigate the optical appearance of natural timbers and planted timbers
  • Evaluation of surface properties of high gloss materials
  • Investigate the optical appearance of textile or fabrics
  • Measurement of the properties of transmittance for diffuser, prism sheet and polarized film of LCD back light.
Optical Conditions & Measurement Examples by Jeffries Method
The GP-200 is an ideal instrument for the Analysis and Quantification
of Appearance, Texture, and Luster on object and material surfaces.
Optical system

By using a condenser lens and the pinhole, the light beam emitting from the light source is collected. After transmitting through the lens, the light beam is collimated.

Furthermore, the light beam passes through the optical aperture and interacts with the surface of the sample. The reflected or transmitted light from the sample surface passes through the telescope lens and the receptor field stop, and reaches the photomultiplier tube. (If the surface of the sample very smooth, an image is formed by the receptor field stop). The reflectance or transmittance of the sample is automatically calculated and reported by the software.		 Measurement Structure

1. Luminous Flux
2. Light Source
3. Receptor
4. Sample Optical system
Halogen Luminous Flux Photomultiplier Tube Measurement Capability Measuring Size Interface

As with all Murakami instruments, integrated control and data processing software
is included with the purchase of the GP-200.
Capabilities Training Services Representation &
Distribution		 Services &
Support		 Meet the People

Avian Optics and Spectroscopy Group