About us

Area of competence

Reliable evaluation of the authenticity of baked clay objects requires, besides complex technical equipment, wide expert knowledge. Authenticity Analyzes of art objects sometimes differ substantially from analyzes of secured scientific findings. There are usually much larger amounts of samples. In addition, it is possible to detect environmental data of storage, which flows into the age calculation. 34 years of TL-analysis of ceramics from such differnt areas as, for example, Chinese, Antique, African or Pre-Columbien culture underlines great experience. The tests for authencity are performed according to the thermoluminecence-procedure (TL). Latest computer technology supports and completes analysis. Thus defination of age is possible with +/- 20-35% exactitude. This is more than sufficient to identify modern imitations.

The certificate

The Ralf Kotalla Laboratory establishes only top quality expert reports. These are outstanding by quickness of analysis, precision of statements and layout. In urgent cases, transportation of objects for analysis or the taking of samples on the spot, abroad or at home, are part of the institute´s extensive service. Regular visits to Paris, Brussels and Zurich round off our service.
In all cases, from the taking of samples to the complete expert´s report, Ralf and Benjamin Kotalla are your partners.

“TL-authentication” – working conditions?


Daybreak 2 xTL 1150; TL 1100;
Alpha – und Betabestrahler Littlemore and 2 Daybreak 801

Corning 7-59 / 5-60; Schott BG-39

Sr 90 40 mC. 101,623 cGy/min on 01.01.2010
CM-244 Curium 0,5 mCi

Corning 7-59 / 5-60; Schott BG-39

Sr 90 40 mCi 101,623 cGy /min 01.01.2010
CM-244 Curium 0,5 mCi

Working method

Fine grain sedimentation following treatment in diluted hydrochloric acid. Grain size fraction following repeated sedimentation 20-50 micro m. Measurements are carried out in an ultra- pure nitrogen atmosphere of at least 4.6 N2 following a previous vacuum of 0,150 mbar.