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Metal coupons and films on day 28. (a) Copper. (b) Silver. (c) Copper film. (d) Silver film. a Humidity controlling agent. b Artificial board blocks for making showcase. c Vanished artificial board blocks covered by aluminum foil (showcase material). d Artificial board blocks for making showcase. e Paperboard for packaging of cultural objects. f Artificial board blocks for making showcase
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Storing and exhibiting cultural heritages are the basic social functions of museum. Since it is impossible to store or display objects without using containers, cases, or holders, the equipment quality is of great importance. Evaluating the suitability of the equipment should not only learn the mechanical behavior but also focus on the materials be...
Citations
... Finally, other methods focus on the characterization of corrosion products formed on Oddy test coupons, aiding in the possible identification of corrosive volatiles emitted by the tested materials. The different characterization techniques include X-ray diffraction [34], µRaman spectroscopy [35], Fourier transform infrared spectroscopy [36], as well as quartz crystal microbalance [37]. Despite the numerous options for scientific analysis of corrosion products and emissions formed during the Oddy test, it is worth remembering that the Oddy test is a tool widely used by institutions without access to that type of instrumentation. ...
Since the introduction of the Oddy test in 1973, many museums and cultural institutions have put the method in use, developing their own versions and protocols. Currently the 3-in-1 version, temperature at 60 ºC and 2 g of tested material are set as common practice; however, other variables of the test are not standardized. The purpose of this study is to examine current versions of the Oddy test, to identify differences in the results derived from variations in the procedures, and ultimately raising awareness within the conservation community to work together towards a standardized protocol. In this article, we review the available information on the methodological differences in Oddy test protocols published in the literature related to glassware cleaning, coupon preparation, reaction vessel setup and rating of materials. Based on the review, and to highlight the many variables that could affect the results of the test, seven European cultural institutions working under the H2020 IPERION HS project performed a comparative 3-in-1 Oddy test by blindly evaluating the same ten materials. Each institution used its own test methodology but some guidelines were advised: (1) Detergents as a cleaning procedure for glassware, (2) P600 sandpaper or micromesh pad close to 1500 to prepare metal coupons and (3) 1:100 as water–air ratio. Despite this, differences between institutions’ results were still observed. Some of them are due to the differences in the coupons preparation, either in the sanding pattern or in the edge area. In order to separate the contribution of the experimental setup and the subjectivity of the evaluation in the discrepancies, coupons from all institutions have been rated by a single team of judges with experience in the Oddy Test. Results show that differences in the evaluation criteria play a relevant role in the discrepancies of the results, especially for institutions with less experience in the test. These results highlight the need to further standardize the methodology and criteria for visual assessment. Nevertheless, the Oddy test has been found to be reliable for the identification of materials that produce emissions hazardous for the conservation of cultural assets.
... Used for Notes Reference X-ray diffraction (XRD) All Grazing angle is required for Ag [11] Raman All Analytical area often small, large numbers of measurements required for representative results [12] Fourier transform Infra-red spectroscopy (FTIR) Cu, Pb [13,14] Image capture and analysis Cu, Ag [8,15] Image analysis of photographs All [16,17] Mass Gain Cu, Pb Issues with different corrosion products providing different mass gains [18] Chemical stripping (mass loss) All [19] Potentiodynamic stripping (mass loss) Cu, Ag [20] Coulometric stripping (mass loss) Cu, Ag [21] Scanning electron microscopy (SEM) All [22] [23][24][25] X-ray photoelectron spectroscopy Ag [26,27] Static Secondary ion mass spectrometry Ag [27] Dynamic Secondary ion mass spectrometry Ag [27] Oxygen depletion Cu, Pb, (Fe) Measurements of the test atmosphere and not the metal coupons [28] All the techniques listed have proved to be able to quantify corrosion, at least on some coupon types. The corrosion layers on silver are often very thin and require sensitive techniques to detect them. ...
Metals are particularly sensitive to some pollutant gases. Many museum showcases and store rooms present atmospheres that can corrode cultural heritage artefacts containing metals. Whilst numerous strategies have been reported to mitigate such situations, avoiding them is preferable. Several approaches to testing materials used in construction, fitting out or dressing are used. The relative merits and drawbacks are discussed. Several parameters of the most widely used, accelerated corrosion ‘Oddy’ test are investigated. The influence of abrasive on subsequent corrosion of lead and copper coupons are assessed. Quantification methods for tested coupons are reviewed. The influence of test duration and temperature are assessed through comparison with real-life, long-term experience of material behaviour. Direct contact tests with touching the test material are investigated. Several materials present in artefacts are known to potentially cause corrosion when enclosed with metals in other artefacts. A number of situations are investigated with pollution and RH and some corrosion rate measurements. Ways to isolate artefacts or mitigate are explored and a decision support model is further developed.
... The assembling of experimental devices and the detailed procedures of the test was described in the previous work [8] . However, the deposited metal films applied to that work were not used in the present study. ...
... Typically, all the copper coupons show a significantly darkened appearance with visible carmine background, which is quite homogeneous on the surface. According to the literature [8] , this corrosion characteristic indicates a corrosion stage between Cu 2 O and CuO while closer to CuO, implying a rather deep corrosion level. On the other hand, the corrosion of the lead coupons is even more serious. ...
Although welcomed and used as storage materials by many museums, camphor wood shows a potential risk to museum collections due to its strong smell. Camphor wood was proved harmful to metals in the author’s previous studies, but since the last study about camphor wood reported by the author, the camphor wood samples have not experienced the Oddy test again for two years, so their harm to metals is unknown at the current stage. Meanwhile, there is no standard or specific method for learning the materials’ effect on organics. The present work focuses on the above situation. Camphor wood samples of different species and aged for different years were tested in this study. Their effect on metals was assessed by performing the Oddy test. On the other hand, a series of mechanical tests were conducted to learn the camphor wood samples’ effect on paper samples commonly used in Chinese calligraphy and painting and the corresponding restoration. The results show that the camphor wood samples are still significantly volatile and harmful to both metal and paper. This work would be meaningful to museum curators and conservators as a reference for making correct judgments when camphor wood is included in the potential material list.
... The experimental setup used for the verification of chemical safety was inspired by the Oddy test protocol for conservation materials [58,59], and a recent refined setup was adopted [60]. Three kinds of samples were prepared: ...
The fracture of a bronze object is usually accompanied by localized deformation. The deformed part often tends to spring back at an unpredictable moment after its shape is corrected. The reconstruction of the area adjacent to the damage should be sufficiently resistant to the stress derived from springback so that the whole structure can remain stable. However, the choice of gap-filling materials for bronze objects is typically based on personal experience, and there are few available studies on their pertinent properties. The present study focused on a typical situation of deformation, took the flexural modulus as a crucial parameter and explored the development of a protocol for selecting a gap-filling material for bronze restoration in terms of its mechanical property. The flexural modulus was measured for the main classes of materials in use, and the factors related to preparation that influenced performance were studied. Among the various materials tested, carbon fiber reinforced (CFR) materials exhibited an advantageous value of the modulus and notable operational convenience. Further tests were conducted to assess their chemical safety for application in a museum context, as well as their surface workability. After obtaining overall encouraging results, composites reinforced with CF cloth and chopped CF were applied to the reconstruction of different parts of an archaeological bronze vessel. Indications for future improvement in the experimental setup and some practical notes regarding the use of CFR materials were also provided in this paper.
... While the most recent protocols from the BM and the Met are described thoroughly and address many of the factors that lead to inconsistent results for Oddy testing, over 20 other test methods are used in museums throughout the world [2,3,6,7]. Some Oddy test procedures vary significantly from the original protocol with, for example, coupons being in contact with the material or removed from the reaction vessel before they have reached the full 28 days [8]. In an experiment conducted by the BM, researchers found that for the same test material, different Oddy test procedures can lead to different levels of corrosion [9]. ...
The Oddy test is an accelerated ageing test used to determine whether a material is appropriate for the storage, transport, or display of museum objects. The levels of corrosion seen on coupons of silver, copper, and lead indicate the material’s safety for use. Although the Oddy test is conducted in heritage institutions around the world, it is often critiqued for a lack of repeatability. Determining the level of corrosion is a manual and subjective process, in which outcomes are affected by differences in individuals’ perceptions and practices. This paper proposes that a more objective evaluation can be obtained by utilising a convolutional neural network (CNN) to locate the metal coupons and classify their corrosion levels. Images provided by the Metropolitan Museum of Art (the Met) were labelled for object detection and used to train a CNN. The CNN correctly identified the metal type and corrosion level of 98% of the coupons in a test set of the Met’s images. Images were also collected from the American Institute for Conservation’s Oddy test wiki page. These images suffered from low image quality and were missing the classification information needed to train the CNN. Experts from cultural heritage institutions evaluated the coupons in the images, but there was a high level of disagreement between expert classifications. Therefore, these images were not used to train the CNN. However, the images proved useful in testing the limitations of the CNN trained on the Met’s data when applied to images of coupons from different Oddy test protocols and photo documentation procedures. This paper presents the effectiveness of the CNN trained on the Met’s data to classify Met and non-Met Oddy test coupons. Finally, this paper proposes the next steps needed to produce a universal CNN-based classification tool.
Graphic Abstract
... However, these equations, known as damage or dose/response functions are very difficult to establish for indoor environments due to the high number of pollution parameters [12] . A different approach is to characterize corrosion products on the metal coupons by superficial analysis techniques such as μRaman spectroscopy [13] or X-ray diffraction (XRD) [5] . These are quantitative phase analysis methods, however the thickness of the corrosion layer must be thick enough to be analyzed. ...
The Oddy test is a preventive conservation tool that helps to preserve real objects of cultural significance. To do this, it uses silver, copper and lead coupons as corrosion dosimeters. Despite its utility and extensive experience, one of its limitations is the lack of a quantitative assessment method to avoid the subjectivity of visual examination and numerically rank the tested materials into suitable (permanent or temporary) and unsuitable. To address these issues, we present a proof of concept for the incorporation of the methodology of the ISO 11844-2 standard into the assessment stage of the '3 in 1′ Oddy test. And so, use standardized quantification methods of corrosion rate for metal coupons such as electrochemical reduction for silver and copper coupons and gravimetric methods for lead coupon.
A traditional '3 in 1′ Oddy test has been performed to evaluate four materials known for their harmful nature to metallic cultural heritage: oak wood, medium density fibreboard (MDF), wool and leather. The electrochemical reduction method yields excellent results for copper and silver, allowing quantifying the corrosion even for the lightest tarnishing of the metal coupons that act as control or reference. For example, in the absence of contaminant-emitting material, the silver coupon lost 0.12 nm of thickness due to corrosion of the own conditions of the Oddy test (60 °C and 100%RH). Mass gain is also a convenient method with enough sensitivity to rank the corrosion of lead.
It has been shown that the ranking established by visual inspection alone can be misleading, rating similarly materials that produce large differences in corrosion rates. Moreover, in the case of copper, the visual rating of the tested materials does not agree with that obtained from electrochemical reduction. Further research is needed to establish the limits of this methodology, but results presented here demonstrate the feasibility and utility of this approach.
... The reliability of camphor wood samples was judged by conducting an improved 28-day Oddy test. The preparation of wood sample bricks and metallic coupons, the assembling of experimental devices, and the testing process were based on the reference (Shen et al. 2018). Typically, several customized glass bottles equipped with ground glass stoppers were employed. ...
... Acids, air, and water play requisite roles in the conversion. According to the reference (Shen et al. 2018), the key reactions can be generalized as follows: Content courtesy of Springer Nature, terms of use apply. Rights reserved. ...
Camphor wood is welcomed by museums due to its insect-repelling effect but the smell indicates a potential risk to the collections. In order to judge the suitability of camphor wood as a museum storage material, typical camphor wood (Cinnamomum camphora) samples aged for different years were evaluated by conducting the Oddy test. Gas chromatography–mass spectrometry (GC-MS), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and time of flight–secondary ion mass spectrometry (ToF-SIMS) were applied to identifying the volatile organic compounds (VOCs) emitted by the materials and the corrosion products, respectively. The results showed that the camphor wood samples led to visible corrosion on copper and lead coupons. GC-MS indicated that the major VOCs emitted were terpenes and their derivatives, while XRD, EDS, and ToF-SIMS provided various clues to the corrosion mechanisms. Pb10(CO3)6(OH)6O and CuO were regarded as the major corrosion products of lead and copper coupons, respectively. The study provides the museum curators and the conservators with abundant information to reassess the application of camphor wood to museums as well as a different way to understand the mechanism of metallic corrosion caused by camphor wood.
... The assembling of experimental devices and the detailed process of test were described in the previous work [6]. However, the deposited metal films applied to that work were not used in the present study. ...
... On the other hand, pattern baselines for the lead coupons were generally similar, but new diffraction peaks were obviously found on the patterns of the affected lead coupons, while the original peaks for lead were significantly weakened, especially on that related to the Cinnamomum glanduliferum sample. The new peaks corresponded to plumbonacrite [Pb 10 (CO 3 ) 6 (OH) 6 On the other hand, the XPS results provide further information about the corrosion. Since different camphor wood samples led to similar corrosion products (reflected by the XRD patterns), it is feasible to collect the XPS spectra for coupons affected by one sample (Cinnamomum glanduliferum) only. ...
... Aqueous extraction pH value of the Cinnamomum camphora samples increases along with the aging of sample, while the Cinnamomum glanduliferum sample presents stronger acidity in aqueous extraction. The corrosion products include CuO and Pb 10 (CO 3 ) 6 (OH) 6 O respectively for copper and lead coupons, while the silver coupons are resistant to the volatile matters. It is necessary to further study the corrosion mechanisms, such as the role of specific volatile components, so that the manufacturers and the conservators will be clearer about the modification strategy for the camphor wood materials. ...
Camphor wood is a traditional storage material used in Chinese museums for repelling insects and inhibiting moulds. Since camphor wood continuously emits volatile matters, it leads to potential risks to museum collections on the other hand. Oddy test was conducted in this study to evaluate the reliability level of four different camphor wood samples for museum use. The samples were put into water and the pH values were measured in order to learn the acidity of each sample preliminarily. Modern instrumental methods including gas chromatography – mass spectrometry, X-ray diffraction and X-ray photoelectron spectroscopy, were employed to identify the volatile matters emitted by each sample and the corresponding corrosion products, respectively. The identification results were discussed together to infer possible corrosion mechanisms and evaluate the effects of aging time and species. The results showed that compared with the Cinnamomum camphora samples, the Cinnamomum glanduliferum sample led to higher risk to the metallic objects, while the reserve of acetic acid tended to decrease along with continuous aging of the Cinnamomum camphora sample but the risk did not decline significantly.
... The level for human safety is parts per million, whereas damage to the heritage has bee correlated with concentrations of parts per billion [11]. The most common studies are related only to organic acids and aldehydes on metals [11,32,33]. ...
The 19th-century building housing the National Archaeological Museum (MAN) of Spain located in Madrid’s downtown was remodelled between 2008 and 2014. During the final of the reform and since its opening to the public on April 2014 and until 2017, the levels of forty different Volatile Organic Compounds (VOCs) were determined and quantified following the AirArt project. This project aimed to identify, quantify and treat the chemical and biological contaminants in the museum. This article discusses the presence, quantification and chemometric studies of the main VOCs identified in the museum. The campaigns were carried out by collecting active and passive air samples on sorbent tubes and monitoring the results over four years. The I/O ratio > 1 shows that the indoor VOCs concentrations were higher than those at the outdoors of the museum from the emission of new materials used for their renovation. The Egypt and Reinos Cristianos rooms have the highest I/O ratio. The PCA analysis for four years of indoor and outdoor VOCs analysis of the museum explains the difference between the two environments and highlighted the siloxanes and aldehydes like principal VOCs inside the museum. The concentration of these compounds is below the WHO limits, but little is known about the limit and which compounds can damage the heritage in the museums. The filtration system in the airtight showcase ensures the removal of pollutants over time, avoiding damage to both the health of conservatives and the heritage on display.
Soluble copper ions in oil pose a significant filtration challenge, potentially exceeding the threat from suspended copper particulates. However, past research has predominantly focused on the impact of metal particles on insulating oil performance, largely overlooking soluble copper ion formation mechanisms and their adverse effects on insulating oil degradation. This manuscript presents an experimental investigation into the formation mechanism of soluble copper ions in oil considering the influence of corrosive sulfide (notably DBDS) and acids (oleic acid and formic acid). Our findings reveal that oleic acid can react with copper to form copper oleate, which has a high solubility and excellent diffusibility in oil. DBDS and formic acid corrosion products exhibit low oil solubility, precipitating as particles or growing on the surfaces. A synergy between DBDS and acids was observed in the copper corrosion process, as evidenced by the sulfur content change in the corrosion products. The simultaneous addition of both acids peaks surface sulfides proportion, but formic acid surprisingly impedes soluble copper formation. This article contributes to a better understanding of the formation mechanisms of soluble copper in the corrosion process within oil, as well as identifying the decisive factors influencing the generation of soluble copper.
