Achaeometrical Research in Hungary II., 1988

PROSPECTING and DATING - Balázs ERDÉLYI: Authenticity research by thermoluminescent method of some works of art with unknown condition of finding from the antique selection of Museum of Fine Arts

method and sample sizes were not sufficiently great for the quartz-inclusion method we adopted. The equipment applied was TLD-04B made by the Central Physics Research Institute (KFKI, Budapest) connected to a Commodore 64 computer equipped with a display and a line-printer linked using a special interface.

3. Measuring parameters: Heating speed 10°C/s Maximal heating up temperature 400°C Keeping it on a maximal temperature 5s The beta dose was measured for half a year by a CaS0

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: Dy TL-dosimeter placed into the bore-holes of the works of art in a polyethylene tube. The dosimeters put into the airspace of the rooms measured the background radiation (gamma+cosmic). The radiation dose measured in the work of art and reduced by the background provides the inner radiation of the work of art. Simultaneously, we used the dose-value of the background radiation with the consideration of the gamma+cosmic radiation. The adequate environmental dose component is practically unknown, thus one must reckon with the opportunity of a major bias. Since in the absence of an appropriate measuring apparatus we took alpha radiation into account only on the basis of data published in the literature, our results are suitable for deciding authenticity only rather than for the purposes of exact dating. Results Table 1. ED (mGy) Dß (mGy/year) Dy+k (mGy/year) D (T-a) Da* Age ED (mGy) Dß (mGy/year) Dy+k (mGy/year) D (T-a) o30% a40% o30% a40% 4980 0,7748 1,099 1,8738 0,8031 1,2492 1860 2090 min 6620 max 9528 1,1100 1,099 2,2090 0,9467 Dr=3,1557 1,4726 DT=3,6816 mm 2098 max 3019 mean-2559 min 1798 max 2588 mean=2J93 mean 1-4=2376 11550 0,4597 1,2435 1,7032 0,7300 DT=2,4332 1,1354 Dr=2,8386 4747 4069 9630 0,6890 1,2435 1,9325 0,8282 DT=2, 7607 1,2883 DT=3,2208 3488 2989 Da* - the 30% value is based on E. Pernicka - G. A. Wagner (the mean of the issued measurement : 28.4% the value of 40% - Aitken : Physics and Archaeology p. 93) Based on the results and glow curves, it is obvious that due to the inaccuracies of measurements (resulting from the many estimated values and the minimal amount of material sampled) our procedure is unsuitable for absolute dating. But it is suitable for the purposes of deciding whether the studied piece is authentic. This hypothesis is supported by correspondences between our results and the art-historical, stylistic chronology as well as the examination of the glow curves. Fleming showed that the condition of authenticity is the evidence of a stable TL-sign at high-temperatures (Fleming, Jucker, Riederer, Archaeometry 13 .7, 1971). 54