Fabrics Spectral Properties
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Background Modern techniques named tele-spectroradiometry or non-contact spectrophotometry are new sources of spectral radiant energy data with more close agreement with actual visual assessment, because they can set up at the same position as was occupied by the observer's eye, and direct it at the object while it is illuminated by the same illuminant in the same surroundings and scenes.
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Presentation Thanks to recent developments on UV LED light sources, new solid state detectors arrays and new thin film technologies, we built a customised mini spectrofluorimeter to accurately determine, in absolute terms, spectroscopy properties of fluorescent materials (like white fabrics) full traceable to international standards, at two different measurement areas: 600 mm2 and 6 mm2. Specifically the new equipment is working on spectral characterisation of:
Absolute spectrometric properties of very small fabric areas (around 6 mm2), like the strip-shaped remanent collar and cuffs stained area after some process of wash, and its fabric surrounding, are obtained with this system, which are critical to understand the consumer cleanliness perception under real laundry visual scenarios. Additionally, accurate determination of fluorescence spectroscopy properties like: fluorescence emission profile, quantum absorptance function, quantum yield, and total, reflected and luminescent radiance and radiance factors coming from the fabric and capable to reach our eyes, under relevant sources of illumination, including different phases of daylight, constitutes the foundation to understand, model and simulate consumer whiteness and cleanliness perception. The equipment is calibrated periodically at DETERTEC using secondary calibrated standards lamps: deuterium, halogen, mercury and argon, all traceable to international primary standards. Additional traceability is provided with comparison of results with data coming from recent developed reference spectrofluorimeters at standardisation bodies.
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Examples 1. Absolute fluorescence emissions profile Y=uW/(cm2*nm*sr)
2. Quantum absorptance function
3. Quantum yield:
4. Spectral total, reflected and luminescence radiance under natural daylight Y= uW/(cm2*nm*sr)
ILL, spectral total radiance of the
source of illumination, real natural daylight, reflected
from a perfect diffuser 5. Spectral total, reflected and luminescence radiance factors (SRFs)
SRF.ILL, spectral total radiance factor
of the source of illumination, real natural daylight,
reflected from a perfect diffuser
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