The Bidirectional Radiometric Scanner

Our newest optical instrument for measuring the angular light distribution of lamps and the angular transmittance/reflectance of arbitrary materials:

• light scattering of optical components
• angular distribution of light emitters
  light distributions curves of LEDs, LCD/CRT/TFT displays, cold cathode fluorescent tubes, anything up to a surface size of approx. 0.5m x 0.5m
• Material (BRTF) measurements, reflectance
  paint, metal surfaces, aluminium reflectors
• Material (BRTF) measurements, transmittance
  translucent glass, fritted glass, screens, holographic materials

This scanner is a custom made version of a design produced by the pab consultancy. This version will be able to span the full solar spectrum with high speed, precision and angular resolution. Some of the principles of operation are based on an early scanning radiometer developed by LBNL (see historical note below).

Current Status: The mechanical parts were fabricated in one of the largest metal presses in Germany.  Two instruments were then assembled. One will remain with the developer for ease of parallel testing and debugging. The final connections of the electrical and mechanical systems will take place at LBNL in April 2008. The following sequence of images chronicle the creation of this unique device.

Figure. Metal Press

Figure: Fabrication of metal parts.

Figure: Twin instruments.

Figure: Approximation of finished product