Experimental Measurement: Interpreting Extrapolation and Prediction by Accelerated Aging

Abstract

The present is the intersection of the past and the future. Correspondingly, the past influences the future as one of several possible actions is selected to be realized at present. The restorer preserves the witnesses of the past to become a source of innovation in the future.Restoration itself, however, has its own past. The art of restoration of former times afiects the future. In restoration decisions are made today that will be of importance when future generations of restorers handle the objects restored. New techniques are applied (or not applied) in restoration and we attempt to predict their usefulness using accelerated aging. PIECES OF ART AS COMPLEX SYSTEMSBerger & Zeliger 1 address restorers of oil paintings, but many points are of interest to restorers in general. Berger & Zeliger consider an art masterpiece to be a complex entity. Correspondingly, they do not just examine the aging behaviour of linen itself but also the aging behaviour of linen coated with adhesive. They find that beeswax under aging conditions of 54°C for 1 year protects the texture and that 94°C for 5 d destroys the texture. Coating the linen with a high-melt adhesive (Thermogrip) produces the opposite result: protection at 94°C for 5 d and destruction at 54°C for 1 year. Baer et al. 2 have done similar work on the system of paper and adhesive.The aging behaviour of the complex system of paper (or linen) and adhesive not only depends on temperature but also on the structure of the fabric, the composition of the surrounding atmosphere, the history of the system, and so on. Applied engineering in manufacturing industry examines such complex coupled systems by using statistical methods of planning and interpreting experiments (factorial design).

Effects of NO2 and acetic acid on the stability of historic paper

“…The broad uncertainty intervals are not entirely surprising due to the number of steps in the experimental procedure where uncertainties are introduced. The Arrhenius approach, used to predict the remaining lifetimes of paper has been criticised in the past, partly due to extensive prediction errors (Ströfer-Hua 1990;Porck 2000;Bégin and Kaminska 2002). One of the arguments was that activation energies should be determined more precisely if they were to be used for predictions.…”