Applications of Micro-Raman Spectroscopy in Cultural Heritage – Examples from the Laboratory for Conservation Research of the Collections Centre of the Swiss National Museums

The paper reports on three applications of micro-Raman spectroscopy which were carried out in the Laboratory for Conservation Research of the Collections Centre of the Swiss National Museums. The first application addresses archaeological questions about three early mediaeval fibulae which were decorated with gemstones. The determination of different corrosion products on pigeon cameras by micro-Raman spectroscopy is described in the second part of this article. The last case study discusses an example from the field of preventive conservation where changes on metal coupons from the so-called Oddy test were analysed

New insights into early bronze age damascene technique north of the alps

Damascening, defined in this context as the inlay of one metal into a different metal base, is a rare decorative technique in the Early Bronze Age, known only from seven bronze artefacts found north of the Alps. This paper reports on the first thorough scientific examination of one such find, the axe from Thun-Renzenbühl grave no. 1. This interdisciplinary project involving several institutions in Germany and Switzerland investigated the axe by means of neutron radiographic imaging and X-ray microprobe methods, supported by microscopic examination. The result is an attempt to reconstruct the fabrication and decoration process and to reconsider the enigmatic question of the origins of the damascene technique north of the Alp

To play versus to display - Historische Blasinstrumente aus Messing im Spannungsfeld zwischen Konservierung und Nutzung

Dieser Artikel stellt ein laufendes multidisziplinäres Forschungsprojekt mehrerer Schweizer Institutionen vor, das sich mit der Erhaltung historischer Blechblasinstrumente und deren Verwendung in der historisch informierten Aufführungspraxis auseinandersetzt. Es wurde 2013 begonnen und steht heute etwa in der Mitte seiner Laufzeit. Zu Projektschluss im März 2017 werden Vorgehen und Resultate im Rahmen eines internationalen Symposiums in Bern vorgestellt. Finanziert wird es vom Schweizerischen Nationalfonds

Analyse chimique de la hache de Fălciu - Résultats et commentaires

International audienc

Analyse chimique de la hache de Fălciu - Résultats et commentaires

International audienc

La perle en cuivre de Besançon/Roche-d'Or (Doubs, France)

International audienc

La perle en cuivre de Besançon/Roche-d'Or (Doubs, France)

International audienc

Breathing New Life into Historical Instruments. How to Monitor Corrosion

Brass instruments of the 19th and early 20th centuries are getting more and more used to being played in historically informed performance practice. In the case of a brass instrument, a musician’s hot, wet breath could worsen the instrument’s interior corrosion, but little is known about this danger. Monitoring the corrosion state inside these historical brass instruments before and after being played is essential for checking the efficiency of preventive conservation protocols. As corrosion of metal artefacts is an electrochemical process, electrochemical techniques are the method of choice, especially since these measurements can be carried out in situ and are non-destructive. In this research, open circuit potential (OCP) and polarisation resistance (Rp) measurements were carried out inside the tuning slides of brass wind instruments in order to monitor the corrosion state and its evolution. The principle and measurement procedure will be described. The initial characterisation of the tuning slides showed a great variation among different tuning slides and also for different positions in a single tuning slide. Thus the surface condition at the (small) point of measurement is more important than the bulk alloy composition. The instruments were then played for several minutes each day: one group dried the inside afterwards each time with a fan, while the control group applied conventional practices. A special electrochemical sensor was developed for the in-situ measurements, combining an Ag/AgCl (pseudo) reference electrode and a small platinum grid as a counter electrode, both embedded in a thin cylindrical sponge mounted on a flexible tube. The sensor had a surface of about 2 cm2 and could be pressed against the inside of the brass tuning slides by a small balloon that could be pumped or emptied. It has been found that the polarisation resistance (log Rp) versus open circuit potential (OCP) plot is a very promising representation for diagnostic purposes that allows us to assign groups of OCP/Rp data from the tuning slides to different surface conditions that have been established in laboratory experiments. Comparing the measurements performed at the beginning, after 7 months and after 14 months of playing, the tuning slides of the instruments without drying showed a constant or increasing corrosion rate over time. On the other hand, preventive conservation, i.e. drying the instruments with the fan, showed constant or slightly lower corrosion rates. This overall positive result has been confirmed with endoscope measurements taken on the inside of the same tuning slides. Note that this result holds as an average on a statistical basis comparing all the tuning slides at the different control times