New spectrophotometer and tristimulus mask colorimeter

Area of Science:

• Optical physics
• Colorimetry
• Spectrophotometry

Background:

• Accurate color measurement is crucial for applications like lighting.
• Existing spectrophotometers and colorimeters have varying levels of accuracy.
• Standardized methods are needed for reliable color data acquisition.

Purpose of the Study:

• To describe a novel apparatus combining spectrophotometry and tristimulus colorimetry.
• To evaluate the accuracy of the developed apparatus for measuring fluorescent lamp chromaticities.
• To compare measurements from the new apparatus with existing methods.

Main Methods:

• Utilized a double grating-mirror dispersion system for spectral analysis.
• Employed three masks aligned with CIE distribution coefficients for direct colorimetry.
• Calculated chromaticities from spectral irradiance data and measured them directly using the masks.

Main Results:

• The apparatus demonstrated high accuracy in both spectrophotometric and colorimetric measurements.
• Chromaticity measurements of fluorescent lamps using the new apparatus showed good agreement with calculations from spectral data.
• Results from the new mask photometer were comparable to those obtained from a mask photometer at NPL.

Conclusions:

• The developed double grating-mirror dispersion system offers a high-accuracy solution for spectrophotometry and tristimulus colorimetry.
• The mask-based measurement approach provides reliable chromaticity data for light sources like fluorescent lamps.
• The apparatus serves as a valuable tool for precise color evaluation and comparison.