Sensor for the control of visible and UV light for worksart

The project "Development of a sensor for lighting control (color and UV fraction of light) in museum environments" is a FISR project. It was perfomed in collaboration with TARGETTI SANKEY S.p.A. and approved by MIUR for the year 2001.

The control of the exposure of works of art to both visible and UV radiation is very important to evaluate the deterioration suffered by these works; it should be noted that any damage depends not only on the amount of radiation to which the work is subjected, but also on the type of radiation because the damage factor depends on the wavelength of the incident radiation.

An example of damage is shown by the work in the photo, where the Coronation of the Virgin by Lorenzo Monaco is shown: the color of the Madonna's mantle from the original mauve has turned white.

When a work of art is illuminated, both with natural light and with artificial light, it can suffer damage, due to the effect of the photochemical action or due to the heating of the work by the radiation.

The causes of damage act differently from work to work, due to the different materials and pigments used.

It is well known that to reduce the damage caused by ultraviolet radiation it is sufficient to limit the spectrum of the radiation incident on the work, however also the visible radiation can cause damage, therefore the monitoring of the radiation incident on a work can be useful for studying the effects of visible radiation on the work itself. This device, once made in an economic version, could be definitively associated with some works of art to have the history of their lighting.

The project involved the control of lighting in museums and the development of a device capable of long-term monitoring both the Visible radiation, to estimate the color rendering, and the UV fraction, linked to the damage factor on the works of art.

Development of an optoelectronic device for measuring UV and visible radiation.
The device includes 5 sensors with dedicated electronics. The first 3 sensors measure the visible light in the Blue, Red and Green spectra. The remaining 2 sensors perform the measurement in the UV range: one with a filter specially designed to transmit the spectrum between 250nm and 400nm, while the other serves for correction. The final version of the device is a stand-alone module that acquires and stores the values ​​of visible and UV radiation.

A prototype of the device carried out a survey campaign on lighting at the Galleria dell'Accademia in Florence.