Double integrating sphere

Luminance reduction


Patented the double integrating sphere system for spectrophotometer calibration

Integrating sphere eq.

Linearity between L1 and L2 are confirmed down to L2~10-6 cd/m2. The lower limit is determined by drift of dark current in the Si photo-detector.

a: radius of connecting pin hole

r: radius of the second sphere

L1: luminance on the first sphere wall to be monitored.

L2: luminance on the second sphere wall to be measured.

Luminance reduction constancy to ensure the photometer linearity over multi decades

Oxide Corporation

Speckle contrast Measurement System