Optical Fiber Sensors for the Cultural Heritage

Conclusions

Two examples of optical fiber sensors for the protection of the cultural heritage were given. The varnished optical fiber could be used also as temperature sensor. In fact, thanks to the good temperature sensitivity and reversibility of gum mastic, it could be considered as a transducer for the implementation of a temperature sensor to be permanently inlayed in the painting. By embedding the optical fiber in the painting together with the picture varnish for example on a comer, continuous temperature monitoring could be possible, in order to prevent risk conditions that can arise when illuminating the painting with the use of lamps, as happens during television shots.

The fiber optic sensor for monitoring of lighting in museum environments has demonstrated its functionality in real operational conditions. Another application of the sensor for safeguarding the cultural heritage, is for lighting monitoring during artwork restoration. In fact, restoring procedures are performed under high illumination, although for a short time compared to the life of the artwork. Since there are regulations also on excessive lighting for short times, continuous monitoring can indicate when the exposure is becoming too excessive. The low cost of the technology involved, indicated as a further development of the sensor an implementation as a battery-powered unit to be permanently installed where critical conditions are feared.

In addition to temperature and lighting, other parameters of interest for the monitoring of museum environmental conditions are: humidity, sound, vibrations and air pollution, especially particulates and gaseous pollutants such as sulphur dioxide, ozone, nitrogen oxides.