4.5 Kunst- und Kulturgutanalyse
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- Beitrag zu einem Tagungsband (14) (entfernen)
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- Humboldt Codices (3)
- Ink (2)
- Odour (2)
- Perceived intensity (2)
- XRF (2)
- 3D inspection (1)
- ATR (1)
- Analytik (1)
- Archaeological provenance (1)
- Building material (1)
Organisationseinheit der BAM
Round robin tests of odour and VOC emissions from building products – What have we learned so far?
(2023)
Emission testing of volatile organic compounds (VOC) and odour from materials and products is commonly based on emission test chamber measurements. These measurements are often the basis of mandatory or voluntary labelling procedures. To ensure the comparability of results from different testing laboratories their performance must be verified. For this purpose, round robin tests (RRTs) are conducted. Bundesanstalt für Materialforschung und - prüfung (BAM) offers such a RRT every two years using well characterised test materials with defined VOC emissions. In addition to the VOC quantification, the evaluation of odour is also implemented in the round robin tests. At the beginning, only perceived intensity (PI) was tested but over the years also the acceptance evaluation was considered. In principle, the results of PI and acceptance evaluation are comparable. The advantage of PI is the lower number of panel members necessary for one evaluation.
VOC-emissions and their odours from building products and furnishings present indoors should not have an impact on personal well-being or health. Odours can be measured by applying the standard ISO 16000-28. Indoor air determination of odour emissions from building products using test chambers. One of the described procedures is the assessment of perceived intensity using a comparative scale by a group of panellists. In this paper, the perceived intensity sampling procedure and its evaluation method are investigated and shown to need improvement. New technical developments in the methodology used to increase the reproducibility of measurement results are discussed. Since odour tests are used for labelling, they have a major influence on the assessment of construction products, similar to the procedure of the German Committee for Health Evaluation of Building Products (AgBB). In the original ISO standard, the evaluation is typically performed using a sampling container separated from the emission chamber. For a better sample presentation, an adapter was developed to connect the emission test chamber to the evaluation funnel and thus enable an odour assessment which is comparable to a direct measurement. The investigations show that losses of odourous substances can be greatly reduced, which is very desirable when seeking to obtain reliable results in odour measurement. Another experimental series was carried out to reduce the measurement effort in the evaluation of perceived intensity. Application of the developed greater than or less than/equal to. query could be helpful here. The results show that the query mostly leads to the same result as the evaluation of the perceived intensity using the method according to the standard but is much easier to perform. Overall, the results can contribute to improving the acceptance of the evaluation of perceived intensity using ISO 16000-28 and to determining odours from building materials increasingly more precisely.
Hundreds of papyrus rolls, carbonized during the 79CE eruption of Mount Vesuvius, were discovered in 1754 at Herculaneum. Sophisticated mechanical methods for unrolling the best-preserved scrolls have been applied, with varying success. However, such processes have been abandoned, to prevent risk from irremediable damage or loss and to preserve the integrity of the extremely fragile rolls. Following the development of X-ray based non-invasive techniques, attempts to virtually unroll the scrolls were made. The most common ink in Antiquity was carbon-based, and the main element of carbonized papyrus is carbon, making these investigations difficult. However, some attempts with synchrotron X-ray phase-contrast tomography (XPCT) were successful. Recently, the identification of antique inks containing metals raised hope that if some of the inks contain metal the rolls can be virtually unrolled using conventional CT- technique. We investigated the inks of a selection of partially unrolled fragments stored at the Biblioteca Nazionale di Napoli with X-ray fluorescence in order to select the best candidates for tomography. Despite the many difficulties (analysis of several layers sticking together, letters barely visible, difficulty to separate contribution from the ink and from the papyrus, inhomogeneity of the support, fragility of the fragments…), encouraging results were found, with a number of inks from Greek fragments found to contain additions to the soot (Fe, Pb, Cu P).
The first manuscripts from the Qumran caves were found in 1947. Within the following 10 years, clandestine and legal excavations revealed some 900 highly fragmented manuscripts from the late Second Temple period. This collection is generally known as Scrolls of the Judea Desert or Dead Sea Scrolls (DSS). For many years after their discovery, text analysis and fragmeents attribution were the main concern of the scholars dealing with the scrolls. The uncertain archaeological provenance of the larger part of the collection added an additional difficulty to the formidable task of sorting some 19000 fragments. After 60 years of scholar research the question of origin, archaeological provenance and correct attribution of the fragmenst are still hotly debated. To dtermine a possible contribution to the debate from the point of view of writing materials, we used otpical and electron microscopy, various X-ray based techniques as well as vibratiional sprectroscopy. We validated our approach with SY - based studies using the advantages of the synchroton radiation source with respect to the benchtop devices. Our laboratory studies showed that often production and storage locality could be distinguished thenks to the specific residues ("fingerprint") they left on the material. Moreover, we have diescovered that diferrent parchment production processses coexisted in the antiquity, and the resulting writing materials can readily be distinguished.
The manuscripts – which have been inventoried as Manuscripta Americana in the State Library of Berlin and the Biblioteka Jagellońska in Krakow with the signatures Ms. Americ. 1-15 – are codices mainly from the colonial times of the 16th to 18th centuries. They uniquely reflect the relationships between indigenous culture and Spanish colonial masters. This study focusses on the scientific investigation of three manuscripts (Manuscripta Americana 3, 8, and 10) that are kept today in Krakow. It is assumed that these three parts belong together in a certain way, so various material analyses were carried out to prove this assumption. The scientific investigation focusses on the different black and brown writing inks.
VIS-Spectroscopy of Aztec colors. Possible application of a non-destructive analytical method
(2020)
VIS-spectrometry is a rapid, non- invasive, mobile method that offers a first overview of possible colorants used for painting. This is worked out in detail for European paintings and applied for artefacts and illuminated manuscripts. Manuscripts from Asia for example show colorful decoration identified to be mostly prepared with mineral pigments such as cinnabar, azurite, malachite or orpiment, which can be well confirmed by elemental analyses due to their color-giving metal ions. This is not the case for the colorants used in pictorial manuscripts from pre-Hispanic America, painted mainly with organic dyes from plants. The palette of colors used by the Aztecs is very rich due to their extensive empire and long- distance communication with vassal states liable to tributes including dyes of high quality. These include for example red cochineal, yellow zacatlaxcalli, tagetes, safflower, and achiotl, as well as blue indigo, or matlalli.
In this poster we will present some results of a research projects dealing with Arabic recipes of black inks. To improve conservation practices of Arabic manuscripts we have assessed the feasibility of the recipes collected from many Arabic sources on bookmaking and reproduced the most common inks. Ink samples were then artificially aged and analysed using an array of analytical techniques, mostly non-invasive, in order to build a database of Arabic inks and their ingredients and also to verify the detection limits of the portable equipment employed.
We will show procedures and problems concerning the identification of ink types and ingredients using reflectography (in Vis, IR and UV), X-Ray Fluorescence, Infrared and Raman spectroscopy. The focus will be in particular on squid ink and mixed inks – both in the form of carbon inks with the addition of tannins and of a mixture of carbon and iron gall inks – which are particularly difficult to detect. We will also examine the results of iron gall inks made with iron filings or nails instead of vitriol, the various precursor used to extract gallic acid that are mentioned in the sources as surrogates of gall nuts.
Unter den von Humboldt in Amerika erworbenen Schriftstücken der Kolonialzeit findet sich eine Tributliste aus dem Jahr 1569, die der Otomí Bevölkerung aus dem Ort Mizquahuala im Staat Hidalgo/ Mexiko zugeordnet wird. Sie ist in Form eines Kalenders ausgeführt, Wochentage und verschiedene Produkte lassen sich unterscheiden. Eduard Seler beschreibt dieses Manuskript zusammen mit einer weiteren Tributliste, die in Inhalt und Zeichnung anders gestaltet ist, jedoch ebenfalls aus dieser Region stammt.
Mit den für die Analyse von Manuskripten bewährten Untersuchungsmethoden werden Papier und Farbmittel identifiziert. Hierzu zählen Raman-, FTIR-, Röntgenfluoreszenz- und VIS- Spektroskopie. Charakteristisch für die Herstellung von schriftlichen Dokumenten in der Kolonialzeit von Amerika ist die Verwendung von indigenem Material wie Papier aus Baumrinde und Pflanzenfarben zusammen mit den aus Europa bekannten Materialien. Geklärt wird, welche Auswahl von Farbstoffen zur Herstellung der Dokumente genutzt wurde, die diese als Gruppe klassifizieren könnte.
Die den beiden Fragmenten zugeordneten Farbmaterialien sowie formale und inhaltliche Aspekte lassen vermuten, dass zwei weitere Schriftstücke der Berliner Sammlung `Manuscripta Americana´, deren Herkunft nicht bekannt ist, mit ihnen in Beziehung gebracht werden können. Stilistisch gleiche Fragmente befinden sich zudem in Mexiko, Paris und den USA.
Im Vergleich dieser Fragmente untereinander wird diskutiert, inwieweit die über die Materialanalyse identifizierten spezifischen Farbstoffe einen Hinweis auf eine gemeinsame lokale Herkunft zulassen.
While studying the socio-geographic history of inks, division 4.5 (Analysis of cultural artefacts and assets) of the BAM (Bundesanstalt für Materialforschung und -prüfung) in Berlin together with the Centre for the Study of Manuscript Cultures in Hamburg has developed a protocol for ink analysis. It consists of a primary screening to determine the type of the ink, and a subsequent in-depth analysis using several spectroscopic techniques.
Using this protocol, scientists can assist scholars in addressing a rather broad range of historical questions that cannot be answered unequivocally through scholarly research alone. Among these are investigations on collaboration between scribes and scriptoria, on the usage and annotation of manuscripts and on their path through time and space in general. This research can thus help to reconstruct the circumstances of the production of written heritage as well as their history and transmission.
To facilitate the dialogue between the scholars and the scientists a simple optical tool was developed to allow the scholars to perform preliminary ink analysis required for formulation of the question that in turn can be answered by scientific in-depth investigations. In this paper, ink types and their identification method is accompanied by examples of the recent work conducted on parchment manuscripts in the Austrian National Library.
In the recent years multispectral imaging and X-ray Fluorescence element mapping have established themselves as a well working two step approach, when dealing with faded, erased or overwritten text in iron gall ink. During the last years a lot was done to improve the mere technical side of the techniques. Especially in the case of XRF mapping experiments the acquisition speed needed to be increased to allow mapping in the high resolution demanded by the challenges at hand. High resolution in moderate times can now be achieved, but with the price of proportionally increased amount of data that needs to be processed ideally in parallel to the measurement. The classical approach in XRF spectroscopy of elemental fitting of the spectral data does not even come close to fulfill any on the fly processing time constraints and will consume too much processing time in the foreseeable future. In this paper we will discuss the applicability of modern statistical data processing methods to XRF mapping of iron gall ink palimpsests. We will present a comparison of a new approach based on principle and independent component analysis (PCA and ICA) and the standard element mapping method. We will show that a reduction in processing time of almost two orders of magnitude can easily be achieved.