A Light Fixture Color Temperature and Color Rendering Index Measuring Device

TL;DR

This paper presents a cost-effective, lens-free device for measuring the correlated color temperature and color rendering index of artificial light sources, simplifying spectrophotometry and enabling accessible, accurate lighting assessments.

Contribution

The work introduces a novel, simplified spectrophotometer design without optical lenses, capable of measuring CCT and CRI effectively.

Findings

Successfully measured spectral power distributions of various light sources.

Accurately calculated CCT and CRI using the prototype.

Device avoids chromatic aberration issues common in optical lens systems.

Abstract

The correlated color temperature (CCT) and color rendering index (CRI) of artificial light sources are important because they have implications for human biology and professional applications. Although CCT information is generally available for commercial lamps, CRI is commonly not reported. In addition, devices measuring these parameters are difficult to access as they require a spectrophotometer, a commonly expensive device. In this context, the present work designs and builds a meter in detail, from the structural part of the equipment, interface with sensors, and the calculation to the compensation algorithms implementation, aiming to build the dedicated functionalities of a spectrophotometer, which is designed without the use of optical lenses. In addition to simplifying the device, this approach allows measurements free from dispersions caused by chromatic aberrations typical of optical lenses. The prototype obtained proved to be effective, capturing the spectral power distributions of various light sources and calculating their CCT and CRI.