Colour measurement of acid-detector strips for the quantification of volatile organic acids in storage conditions

Acid-detector (A-D) strips were originally developed to assess the deterioration of acetate film stock, but they can also be used more generally within enclosures to detect volatile acidic pollution. A hand-held reflectance spectrophotometer was used to record the colour of individual strips in order to make consistent and reproducible readings. Calibration was carried out using the yellow-blue axis b*(D65) value in the CIELAB1976 system to measure the colour of A-D strips suspended in enclosed containers over solutions of acetic acid in combinations with glycerol to control the relative humidity (RH). A-D strips were found to be sensitive to changes in high RH (60–90%) but affected little by changes in lower RH or temperatures in the museum display and storage range. A-D strips can be used to establish the presence of volatile acids, record the indication of acid vapour concentration, explore conditions within a container, and to find sources of volatile acidity. They respond very quickly and several can be placed around an object. They therefore show promise for measuring slowly changing conditions, such as seasonal changes and the gradual accumulation of acidity in poorly ventilated containers and spaces. A-D strips proved useful in assessing air quality in storage and display enclosures. Examples and test results are presented. Well-sealed plywood transit frames and storage cases were found to be most polluted with volatile acids. Storage rooms with air filtration systems but filled with wooden objects had significantly reduced air quality.     

Biological Pest Control of a Biscuit Beetle (Stegobium paniceum) Infestation in an Old Masters Paintings Storage Area

ABSTRACT

We report on biological control of an active infestation by biscuit beetles (Stegobium paniceum) of museum objects (Old Masters paintings) in the storage facilities of the Museum of Fine Arts in Vienna. Because chemical and non-chemical treatment methods would have been very problematic, the release of parasitic wasps (Lariophagus distinguendus) was discussed and accepted by the director of the collection. We released 3000 wasps every month from August 2013 until September 2014 in the two infested storage rooms and monitored the activity of biscuit beetles on sticky blunder traps and light traps, and also by visual inspection. In the insect monitoring of 2014 until 2018 no more biscuit beetles were found in the two storage depositories, showing that the treatment was 100% successful. To our knowledge, this is the first proof of a fully successful biological control of a museum pest using parasitoids only, and also of stored product/food pest, outside a laboratory experimental setup. This biological pest control method allowed avoiding negative side effects such as contamination from treatments with biocides, or costly logistics in case of chemical-free methods.     

Environmental conditions for the safeguarding of collections: A background to the current debate on the control of relative humidity and temperature

Conditions of relative humidity (RH) and temperature within museums and buildings holding collections of cultural heritage objects are often maintained around a strictly controlled set point of about 50 ± 5% RH and 20 or 21 ± 2°C to provide safe, stable conditions for hygroscopic artifacts. It has recently been proposed that these ranges should be relaxed to values that are less energy-intensive to maintain while still being safe for the objects in the collection, with the aim of reducing both carbon footprint and energy use. It is also suggested that conditions should be determined by the needs of individual objects and by the local climate of the region, rather than applying overall values across the museum as a whole. This proposal has led to much discussion within the conservation community. The suggested values, a stable humidity within the range 40–60% RH and a stable temperature within the range 16–25°C for most objects, apart from the most vulnerable, are derived from the results of experimental research on the responses of individual materials to particular conditions of RH and temperature, as well as observations of the behaviour of cultural heritage objects in their own environments and on loan. This paper describes briefly the historical and scientific background to the present discussion.     

Monitoring Acoustic Emission in an Epidemiological Pilot Study of a Collection of Wooden Objects

ABSTRACT

This experimental program, implemented by the Managing Collection Environment Initiative at the Getty Conservation Institute, has provided data about the response of historic objects to changes in relative humidity (RH). Alongside other less sensitive documentation techniques (visual observation, physical measurements, photography, and 3D scanning), acoustic emission (AE) was monitored for six historic, museum-like wooden objects exposed to gradually increasing RH variations. Quantitative calibration of AE sensors and an anti-correlation measuring scheme to reduce environmental noise allowed the AE system to effectively trace micro-damage development caused by environmentally induced stress. Using an epidemiological approach, with respect to sample selection and experimental protocol, the obtained results can be used to explore the acceptable range of climate fluctuations for museum collections. The study’s well-controlled environmental protocol also allowed for the examination of the concept of ‘proofed fluctuation’ by the analysis of object response to reoccurring conditions.     

The application of vapour-permeable synthetic membranes to the climatic stabilization of museum showcases

Abstract

This paper describes a novel technique to stabilize the relative humidity (RH) of the air inside museum showcases by using a synthetic hydrophobic membrane coupled with a hygroscopic solution in a membrane contactor. RH-monitoring data for two identical test cases, one of them controlled by a set-up with a plane-plate membrane contactor crossed by forced air and lithium chloride (LiCl) solution flows, show a significant stabilizing effect on RH fluctuations. A theoretical model permits forecasts in close agreement with the experimental RH data. Further calculations carried out over a one-year period show that notable damping of external RH variations can be obtained by using a low air circulation rate, small membrane surface area and low solution mass per unit case volume. A more general analytical solution in harmonic conditions is derived and discussed.     

Overview of preventive conservation and the museum environment in China

Based on a nationwide investigation of the current state of preservation of museum objects in China, around 51% of the 35 million museum objects show different degrees of deterioration. Although treatment of objects is necessary, treatment alone is not sufficient. In China's present situation, preventing damage to museum objects is much more cost-effective than allowing damage to happen and then treating it. The number of museums in China is increasing very fast: 23?000 exhibitions are held, 600 million visits are made, and 35?000 archaeological objects are excavated nationwide, each year. At the same time, these museums are widely distributed and have different levels of resources. We need both technical knowledge and preventive conservation to safeguard our precious museum objects. This paper introduces research achievements in preventive conservation, and traces the development of this discipline in China. Starting from the classification of museums in China, legislation is detailed on preventive measures such as selecting appropriate light sources, controlling temperature, relative humidity, light damage, and pollutants. This paper describes achievements in monitoring, analysis, evaluation, and control of museum environments in China. It also proposes future directions for museum environment studies during China's twelfth Five-Year Plan.     

The Influence of Hygroscopic Materials on the Fluctuation of Relative Humidity in Museums Located in Historical Buildings

ABSTRACT

The preservation of artefacts in museum collections is profoundly affected by fluctuations in temperature and, especially, relative humidity (RH). Since the late nineteenth century, many studies have been carried out on the best way to control hygrothermal conditions. In old buildings located in maritime temperate climate zones (such as Portugal) with strong thermal inertia, and which have low ventilation rate (relative to the volume and number of visitors), daily and seasonal hygroscopic inertia may help to assure the maintenance of RH stabilization conditions. The use of expensive active systems may be minimized through the passive behaviour of internal finishing building materials. This work presents the results of an experimental laboratory study conducted in a flow chamber to demonstrate the enormous potential of hygroscopic materials in stabilizing interior relative humidity. Based in these results and in-situ monitoring in a museum housed in a building, located in Porto, with a typical construction of the 1950s (granite masonry and reinforced concrete slabs), a numerical analysis was done to quantify the influence of hygroscopic materials in stabilizing the interior relative humidity.     

A Conversation on Object‐Centered Learning in Art Museums

Danielle Rice and Philip Yenawine are veteran art museum educators who have wrestled for decades with the thorny issues involved in teaching about and learning from art objects in the museum setting. While there is general agreement within art museums today that the object should be the focus of educational practice, debate continues as to the most effective processes for facilitating learning. Gallery teaching is one of the most contested arenas, with much of the disagreement centering on the place of information in teaching beginning viewers. In art museums, the issue of what and how to teach is complicated by the fact that many people, including artists, museum professionals, psychologists and educators consider art primarily as something to be enjoyed, and they posit this enjoyment in direct opposition to learning about art. Partly because of this, the function of art museum education and gallery‐based instruction is still evolving.     

Understanding storage environmental stability during power outages: A key issue in sub-tropical climates

Efficient air-conditioning systems facilitate climate control in modern museums, libraries, and archives. The climate in Hong Kong is typically hot and humid, so the survival of collections is highly dependent on 24-hour air-conditioning systems to maintain the desired environment in repositories of archives and books, or artefact stores. The continuous operation of such systems in turn relies on a number of factors, such as uninterrupted electricity supply, an active maintenance programme, daily monitoring of their performance and quick response to irregularities as well as backup or alternative systems to support the air-conditioning load in case they are down for servicing. From the risk management point of view, unlike the latter four factors, electricity supply is an external factor that cannot be guaranteed. Fluctuation in the power level that results in stoppage of air-conditioning equipment is not uncommon even in well-developed countries. Long power outages could be catastrophic as they might lead to irreversible damage to collection items as a result of fast, large, changes in temperature and relative humidity (RH) towards the external environment if the air-tightness or hygrothermal stability of the storage are not good enough. Understanding storage environmental stability, especially during electrical power disruptions, is an essential part of the preservation measures and disaster preparedness necessary to protect valuable collections in cultural heritage institutions in the region.     

White Collar Crime In Museums

White Collar Crime (WCC) can be defined as crimes committed by employees against their employers. Little empirical research has been conducted into WCC in the museum sector. The majority of a museums collection is held in back‐of‐house storage facilities with only a relatively small number of objects actually on public display. The true extent of WCC is unknown and it is a difficult area because of its complexity and invisibility. The article gives an overview of white‐collar crime, outlines the characteristics and techniques of this type of crime and seeks to identify the problems of controlling white‐collar crime with particular reference to the UK museum sector.     

Portable X-ray fluorescence analysis of pesticides in the textile collection at the German Historical Museum,Berlin

The majority of the objects found in the textiles collection at the German Historical Museum in Berlin have been treated with different biocides at various points in the past. Prior to this study, the presence of organochlorinated pesticides in rooms and storage cabinets had already been proven in an analysis of air samples that employed gas chromatography and mass spectroscopy. To estimate the risks these toxins pose to both collections and museum staff, we conducted a field study with the help of a portable X-ray fluorescence spectrometer. In this study, we present an attempt at a reliable quantitative analysis. In addition to chlorine, other potentially hazardous elements such as lead, arsenic, and mercury were found in the majority of the objects. In some cases, however, it has to be taken into account that the detected elements might have originated from manufacturing processes rather than biocide treatments. Such knowledge is a crucial prerequisite to proper risk prediction.     

A Review of the Physics and the Building Science which Underpins Methods of Low Energy Storage of Museum and Archive Collections*

ABSTRACT

The need to keep things cool for durability should be the single most powerful influence on storage design. The simplest temperature control is to moderate the outside temperature by a combination of thermal insulation and heat capacity. The low energy storage building is a lightweight, thermally insulated, airtight building put on top of an uninsulated floor slab laid directly on the ground. The thermal insulation is calculated to even out the daily temperature cycle but to allow an annual temperature cycle which is about half the amplitude, but much smoother, than the annual temperature cycle outside. The winter temperature inside will nearly always be above ambient and so will maintain a moderate RH without need for either humidification or dehumidification. The temperature inside in summer will be below ambient and thus will force dehumidification of the infiltrating air. However, the airtightness of the building allows intermittent dehumidification with low energy consumption, less than one kWh/m³ per year. There now exist enough buildings designed on this principle to reassure curators that highly valued collections can be stored in a space with a gentle temperature cycle and with an RH stability as good as air-conditioning usually achieves.     

Evaluation of the stability,appearance and performance of resins for the adhesion of flaking paint on ethnographic objects

ABSTRACT

The Natural History Museum (NHM), London was one of the first national museums to introduce a museum-wide integrated pest management (IPM) strategy that includes the concept of risk zones (Doyle, Pinniger, and Ryder 2007). This system is based on the principle of pest prevention within a museum building, which will always have a resident population of pest insects. The loss of Dichlorvos [DDVP] resulted in an urgent need to implement a museum-wide IPM programme to protect vulnerable collections both in storage areas and on display. With such a large, diverse collection in a complex series of interconnecting buildings, it became necessary to break the programme down into sections. Thus the development and implementation of the concept of risk zones: classifying areas of the museum from high risk to low risk has proved a useful and effective method to promote staff awareness and best practice as part of a comprehensive IPM programme.     

Evaluation of Touchable 3D‐Printed Replicas in Museums

The multisensory aspect of the museum, while neglected for many years, is undergoing a resurgence as museum workers have begun to push towards re‐establishing the senses as a major component of museum pedagogy. However, for many museums a major roadblock lies in the need to conserve rare objects, a need that prevents visitors from being able to interact with many objects in a meaningful way. This issue can be potentially overcome by the rapidly evolving field of 3D printing, which allows museum visitors to handle authentic replicas without damaging the originals. However, little is known about how museum visitors consider this approach, how they understand it and whether these surrogates are welcome within museums. A front‐end evaluation of this approach is presented, finding that visitors were enthusiastic about interacting with touchable 3D printed replicas, highlighting potential educational benefits among other considerations. Suggestions about the presentation of touchable 3D printed replicas are also discussed.     

Evaluation of disinfection techniques for the conservation of polychrome sculpture in Iberian museums

Abstract

Insect infestation is a serious problem in museum collections in Spain and Latin America. This paper investigates the efficacy of modified atmospheres as an anoxant for museum pests, using wooden objects including polychrome sculptures infested by Cerambycidae and Anobiidae species. Insects of long life cycle have been found to be very resistant to carbon dioxide atmospheres. However, inert gases such as argon and nitrogen used in plastic barrier bags effectively eliminated insects in all stages of development. No chemical alteration was observed in the treated materials, including polychromy. These treatments are in progress in a project for biodeterioration control in countries with both tropical or subtropical and Mediterranean climates.     

Linking webbing clothes moths to infested objects or other food sources in museums

The webbing clothes moth Tineola bisselliella (Hummel, 1823) is one of the most common museum pests and can be found all over the world. The larvae damages objects made of feather, wool, fur, and other keratinaceous materials. Pheromone traps are important tools in integrated pest management, which allow the detection of infestations and evaluation of their extent. Organic-rich dust (detritus) or other materials of animal origin, such as dead birds, can be an alternative food source for the moths. This paper analyzes monitoring data collected with pheromone traps from six different museums in Vienna and Berlin and tries to differentiate between moths resulting from infested objects or moths coming from other food sources, such as organic-rich dust. Annual totals of moths trapped and catch rate (moths per trap) are important guides for selecting appropriate remedial measures. Long-term data (over six years) enabled us to interpret monitoring results and differentiate between active infestation of objects and cleaning or housekeeping problems. However, detailed knowledge of the site and buildings, availability of high-quality food for the larvae, and lack of regular cleaning are also important factors to consider when interpreting the data.     

Examination of museum objects by means of video holography

Abstract

A prototype inspection system has been tested which makes use of electronic speckle pattern interferometry with computer image processing, for deformation and stress analysis and for the location and analysis of defects in museum objects. Two different examples have been chosen: a nineteenth-century oil painting on a wood panel and a seventeenth-century enamelled terracotta vase. The method can give quite accurate metrological information; it is also particularly promising for rapid qualitative analysis.     

The Authority of objects: From regime Change to Paradigm Shift

Abstract Objects have never been quite as bluntly material as is conventionally claimed. Nothing is just a thing. We carve objects out of a blurry reality as we need them, creating narratives that adhere to them in greater or lesser degree. Traditional museums were held to be “about objects”—which were esteemed as material bearers of accrued significance. Why then the current disputes among museum professionals and observers who question the role of objects? Museums have always been about ideas and about objects. They foster human and physical interactions in which neither persons nor things take precedence.