Fiber optics reflectance spectroscopy
The visual appearance can be one of the most critical parameters affecting esthetical appreciation of an artefact, and it needs, therefore, to be measurable and monitored.
When the lighting system is established, the appearance of an object is given by its colour, gloss and texture. A starting point in assessing the appearance of a museum object might be the measurement of its colour. This will be assessed by a continuous measurement of sensitive object display in museums. The description of its total appearance, however, cannot be achieved by the definition of colour alone; other attributes of the object contribute to the overall appearance and these might include gloss.
FORS is an analytical technique based on the use of portable spectrophotometers equipped with optical fibres accessories. The optical fibres are used to convey the light electromagnetic radiation from the instrumentation to the target and vice versa, thus making it possible to perform measurements in-situ, without any sampling. Thanks to the flexibility of optical fibres, any point of the object can be easily reached and measured non-invasively, without constraints due to size or shape of the artwork.