CPC G01N 21/86 (2013.01) [G01B 11/0691 (2013.01); G01N 21/3559 (2013.01); G01N 2021/869 (2013.01); G01N 2021/8618 (2013.01); G01N 2021/8663 (2013.01)] | 12 Claims |
1. A measurement device to measure a physical quantity of a measurement target with a sheet-like shape, the measurement device comprising:
a first integrating sphere which is separated by a gap from a first surface of the measurement target, has a first opening facing the first surface, and is not provided with a light detector to detect an intensity of light;
a second integrating sphere which is separated by a gap from a second surface of the measurement target, where the second surface is positioned opposite to the first surface, and has a second opening facing the first opening with the measurement target sandwiched therebetween;
a light source unit to emit light into the first integrating sphere;
a light detecting unit to detect an intensity of light inside the second integrating sphere; and
a calculating unit to calculate the physical quantity of the measurement target based on the intensity of light detected by the light detecting unit, wherein
the first integrating sphere includes a first shielding plate adapted to shield a part of the light emitted by the light source unit,
the second integrating sphere includes a second shielding plate adapted to reflect at least a part of the light inside the second integrating sphere to transfer the at least part of the light into the second integrating sphere, and
a length of the second shielding plate is identical to or smaller than a length of the first shielding plate in a longitudinal direction and a width direction of the measurement target.
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