Conservation Apps

Explore this catalogue of open-source, easy-to-use digital tools specifically designed for preventive conservation.

In the digital-age preventive conservators now have access to a wide range of online calculation tools that assist with routine tasks, calculations, and decision-making. This page brings together apps from various places into a curated catalogue of free-to-use online apps for preventive conservation.

Some of the apps featured on this page were part of the IPERION-HS project, preparing to offer digital services within E-RIHS.

Featured Apps

Summary

HERIe – make a measured assessment of risks to heritage.
DISCOLL – model how paper-based collections discolour.
IMPACT – predict the concentration of outdoor pollutants in a indoor space.
Lux Allowance Calculator – check the light that an object or group of objects will be exposed to during an exhibition or display and to help make a lighting plan.
Collections Demography App and Box Buffering Capacity App – predict the remaining useful life of paper and storage boxes.

This page is not intended to be exhaustive. If you have suggestions for an app that should be listed, please contact josep.grau.bove@ucl.ac.uk.

Detailed overview

HERIe

HERIe provides remote access to quantitative assessment of risks to heritage assets has been developed to support conservation decisions and is organised in the framework of ten independent modules corresponding to ten agents of deterioration.

Limitations

Mechanical damage module can evaluate risks of environments with temperatures below 25 oC and RH below 75%.

Input

IMPACT tool - the volume of the room, the area of every surface where pollutants can deposit and information on the type of the material, T, RH, and the level of ventilation.
Light damage calculator – light intensity measured over a prolonged period or amount of color sustained in the object, intensity of light, exposure time per day, number of days per year, number of flashes, time horizon.
Chemical degradation tool – one-year (or multiyear) temperature and relative humidity data which can be measured or simulated, type of the material.
Mechanical damage tool – one-year (or multiyear) temperature and relative humidity data which can be measured or simulated, the type and characteristics of the object.
Fire risk – characteristic of the building, number of objects packed or showcased, the sensitivity of the material to combustion and water and time horizon.

Output

IMPACT tool – the Indoor/Outdoor ratio (%).
Light damage calculator – original and faded colors are presented as patches on the computer screen in time horizon.
Chemical degradation tool – the expected lifetime and the relative expected lifetime for a range of low stability materials: wood pulp-based papers post-1850 and cellulose acetate. For a general category of low-stability organic materials, the tool provides only a relative expected lifetime.
Mechanical damage tool – strain versus time histories with the failure criteria.
Fire risk – expected loss of collection value expressed as a part of the collection in time horizon.

Since 2014, the HERIe platform has been developed in the framework of several projects funded between other by the European Commission and the Getty Conservation Institute. Since 2020, the HERIe platform is being developed in the framework of the EU IPERION HS project. Also, several tools have been implemented on the platform within the IPERION HS project including the fire risk tool, IMPACT tool and chemical degradation tool. The platform is widely used across the international conservation sector, so far there are 600 registered users, and 2000 unique climate data were uploaded and analysed.

DISCOLL

DISCOLL is a research tool for modelling paper-based collection discoloration. This works on a wide spectrum of paper form colour photographs to historic paper. It comprises two fundamental functional modules:

Lifetime Explorer (LE) – adeptly forecasts discoloration over time, considering multiple environmental factors such as oxygen concentration ([O2]), temperature (T), relative humidity (RH), acetic acid (AA), and illuminance (Ev). It facilitates the exploration and comparison of diverse strategies tailored to specific display and preservation objectives.
Uncertainty Analyser (UA) –diligently assesses how variations in each environmental factor impact discoloration. By identifying the factors with the most substantial influence, it enables focused efforts and resource allocation toward effective reduction of discoloration variation.

These modules empower users to visualize the temporal evolution of discoloration, probe the collective impact of environmental factors on discoloration patterns, and gauge the effect of fluctuations in these factors on the degree of discoloration variation.

Limitations

DISCOLL currently possesses the capability to analyse three types of material categories: historic paper, iron gall ink, and colour photographs. For the former two, the analysis encompasses the impact of [O2], RH, and Ev, while for the latter, it focuses on the effects of T, RH, and AA.

Input

Lifetime Explorer

Type of material: the material of the collection to be analysed.
Factors: the external factors that affect the discoloration of the material selected.
Upload data file: upload environmental monitoring data if applicable.

Uncertainty Analyser

Type of material: the material of the collection to be analysed.
Scenarios: the environmental conditions specifying the fluctuations of the factors.

Output

Lifetime Explorer

LE generates isofade plots to illustrate the relationship between discoloration and selected pairs of factors. These plots are constructed as contour plots, which serve as effective visualization tools for exploring how different factors collaboratively influence the response of collections. In an isofade plot, each contour line signifies an equal amount of discoloration, with contour line intervals set at 0.1 ΔE00 units. To obtain the precise level of discoloration, users can simply hover their mouse over the area of interest on the plot and read the corresponding values displayed beneath it. Furthermore, if monitoring data is uploaded to the model, one can estimate the expected discoloration level in a specific monitored environment. The resulting plot can then be downloaded for inclusion in reports or for further analysis. This data is instrumental in establishing and refining environmental management plans, particularly in determining damage thresholds and optimization strategies.

Uncertainty Analyser

The UA results are presented through bar plots, wherein the impact direction and relative magnitude for each factor are visually represented by individual bars. A bar positioned on the positive side of the horizontal axis signifies that the factor promotes discoloration, while a bar on the negative side indicates that the factor inhibits discoloration. The length of each bar is proportionate to the extent of its impact, with longer bars denoting a greater influence on the variation magnitude of discoloration. Consequently, factors associated with longer bars should be given higher priority when implementing collection environmental management strategies.

The scope of the heritage materials to be analysed will be extended as more data and models become available. A beta version of DISCOLL is available for testing by request to Yun Liu.

This project was made possible from funding provided by the Smithsonian’s Museum Conservation Institute Trust Funds, USA, which made this research possible. The development of the study was aided by the support and contributions of several organizations, including the Integrating Platforms for the European Research Infrastructure ON Heritage Science (IPERION HS), Heritage Science Laboratory Ljubljana (HSLL), and Science and Engineering in Arts, Heritage and Archaeology Centre for Doctoral Training (SEAHA CDT).

IMPACT

The IMPACT (Innovative Modelling of Museum Pollution and Conservation Thresholds) model predicts indoor concentrations of pollutants. The main output is the Indoor/Outdoor ratio (%), which is the percentage of outdoor pollutant concentrations that we can expect indoors. To find this value, the model estimates the deposition flux of pollutants to surfaces. The deposition flux depends on the type of surface, its area, and the air movement in the room. It also depends on a value known as deposition velocity, which has been experimentally determined for a diversity of common indoor surfaces.

To run a simulation, you need to input the volume of the room, the area of every surface where pollutants can deposit, T, RH and the level of ventilation. Ventilation is expressed in Air Exchange Rate (AER, 1/h), which indicates the number of times in an hour that the air in the room is refreshed.

The model shows the indoor concentration at equilibrium. This means that, in a room with no deposition, the internal concentration will eventually be equal to the external, even if it takes a very long time. The time to equilibrium can be explored with the plot Concentration Through Time. An important assumption of the model is that it does not consider homogeneous indoor chemistry, that is, it assumes that the reaction rates of these pollutants are negligble. This assumption is incorrect in some cases.

Limitations

The IMPACT model is based on deposition rates measured on around 20 different materials. Deposition is highly materially dependent, so it should be applied to different materials with caution. It is designed to be used for exploratory analysis and to understand the relationships between input parameters. However, users who intend to use this model to inform decision-making, are advised to compare the predictions with directly measured concentrations in their spaces. Even a single simultaneous measurement, indoors and outdoors, can be useful to evaluate whether the predictions of the model are reasonable for a specific building.

Input

The IMPACT model requires the following inputs: type of air pollutant, RH, T, AER, outdoor pollutant concentrations, interior volume of the museum and the material and area of different surfaces. Users can select the type of pollutant: NO2, SO2 or O3. Users can determine the type of material and surface area for the walls, floor, ceiling and two other surfaces, for example, paintings or furniture. Users are advised to either measure or obtain outdoor concentrations from reliable sources, such as automatic air quality monitoring stations.

Output

The main output of the IMPACT model is the indoor pollutant concentration in the space of interest. It also provides two visualisations: the percentage of pollutants deposited on each surface and the relationship between AER and I/O pollutant concentration ratio with an interactive curve graph. These two visualisations enable the exploration of alternative scenarios. There are instances where a small improvement in ventilation can have a notable impact on the internal conditions. The IMPACT tool can help identify such scenarios. Another use of the tool is to investigate the amount of deposition that will occur on different types of surfaces, in order to estimate risks to materials. One of the materials of choice in the tool is “canvas paintings”, which is of special interest to conservation.

The current version of the IMPACT model (2) was coded by Josep Grau-Bove, in order to continue offering access to this useful model. The original research was carried out by Nigel Blades, Declan Kruppa, May Cassar (UCL Institute for Sustainable Heritage), and Terje Grøntoft (Norwegian Institute for Air research) (Kruppa, 2002).

Kruppa, D., Blades, N., & Cassar, M. (2002). A web-based software tool for predicting the levels of air pollutants inside museum buildings developed by the EC impact project. In 5th EC Conference, Cracow, Poland.

Lux Allowance Calculator

The Lux Allowance Calculator is used to check the calculated light exposure (in lux hours) for an object or group of objects for a selected period of display. This is based on three parameters:

The type of objects being lit
The number of hours of light needed
The desired light (lux) levels

The period of time can be adjusted, for example, a whole year or just for the duration of a temporary exhibition.

The output from the calculator represent the total light exposure for the selected period rather than just a target lux value. This total represents a planned cumulative light dose or ‘allowance’, that must accommodates normal opening hours, maintenance and security arrangements and out-of-hours activities. To keep the calculated light allowance below the limits given for a particular object type, it may be necessary to limit the number and duration of out-of-hours activities and/or reduce the light levels for the duration of such activities.

Lighting guidelines, in the conservation literature, based on cumulative light exposures are generally averaged out over a typical year and can be combined with an absolute maximum lux level that should not be exceeded. In practice, these limits can be converted into operational lux level limits (or lux set points) adjusted to accommodate the required lighting duration. When preparing a lighting plan, a range of values need to be considered. The cumulative allowance will need to accommodate:

Public opening hours.
Lighting for additional planned out-of-hours events.
Lighting for daily cleaning and maintenance.
Lighting for overnight and security patrols.
Additional lighting for unforeseen events.

Limitations

It's an automatic web-based tool, some minor customisation is possible and is described in the instructions, but for more complex adjustments one would need to download the source code.

Input

The dates of the period of interest Tthe class of objects being considered The hours of exposure The relevant lux set points and limits.

Output
A text-based description of the total estimated lux exposure for a defined period of exposure. The description also includes comments related to over exposure, required offsetting and options for exploiting any unused allowance.

The Lux Allowance Calculator was developed by Joe Padfield at the National Gallery.

Collections Demography App

The Collections Demography App supports preventive conservation decision-making in the context of storage in large archives and libraries. On the basis of environmental inputs (temperature, relative humidity) as well as material properties (paper pH and degree of polymerisation - DP), the app returns the predicted remaining useful life of paper. This is calculated as the time it takes until the particular paper reaches a critical DP value that no longer allows safe handling, at the given environmental conditions.

A typical threshold value for the degree of polymerisation that allows safe manipulation of a sheet of paper in the context of reading in a library or in an archive, is 300. If the material properties are unknown, the tool offers a number of pre-set options based on “typical” categories of Western paper, i.e. rag, lignin-containing, bleached and contemporary paper.

Based on the input long-term planning horizon, plots of suitable T and RH are calculated that support the retention of paper material properties that enable safe use into the future.

The app also enables the calculation of the remaining useful life for entire collections. Users can either input their own data or explore preservation scenarios using sets of data measured in surveys of case study collections.

Limitations

The service is designed to perform optimally within the following environmental conditions: 20% > RH > 80%; 5 oC > T > 35 oC

Input

To model the RH fluctuation within a chosen box, the users need to input the maximum environmental RH fluctuations they would need to buffer, e.g. +/-30% in an exposed environment, such as a church, or +/-20% as experienced in country houses or open, nonpurpose built storage areas etc.; and the allowable fluctuation within the box, e.g. +/-10%.
The app then calculates whether the selected box has suitable RH buffering properties. This allows users to select boxes and other enclosure materials that are suitable for sustainable, low-cost management of storage microenvironments.

Output

Remaining useful lifetime of paper: time (at set T, RH) untilunacceptable risk of mechanical damage for diverse types of paper.
Demographic plots for collections, consisting of mixed paper types, e.g. rag, acidic, deacidified, contemporary paper.
Effect of deacidification on the demographic plots for collections of paper.

The fundamental concepts used in the Collections Demography App were developed in the frame of the UK AHRC/EPSRC Collections Demography project (Strlic, 2015). The development of the app was carried out by the Heritage Science Lab Ljubljana (University of Ljubljana) and UCL Institute for Sustainable Heritage, in collaboration with the Smithsonian Institution’s Museum Conservation Institute and the Library of Congress

Box Buffering Capacity App

The Box Buffering Capacity App supports the estimation of suitability of archival boxes and other enclosures to buffer fluctuations of RH within the box/enclosure, in the context of preventive conservation decision making.

The app calculates the RH with the enclosure on the basis of a mass transfer model assuming that temperature does not have a major effect on the transmission of humidity through structural openings or through the box material.

The app allows us to calculate the HA index – humidity attenuation index – an index that describes the buffering capacity of a box, the closer it is to 100, the more stable the RH within the box is, regardless of RH fluctuations outside the box.

Users can explore the properties of boxes either using the pre-set HA indices or they can calculate their own HA index for the material of choice, on the basis of a set of RH measurements within and outside the box of interest.

Limitations

The service is designed to perform optimally within the following environmental conditions: 20% > RH > 80%; 5 oC > T > 35 oC

Input

Output

Calculation of the Humidity Attenuation Index for a selected box (material type, size, construction type) and evaluation of the RH buffering capacity in environments with unwanted RH fluctuations.
Service Input Description Environmental data: RH, T Material data: paper pH, degree of polymerisation

The Box Buffering Capacity App development was funded by the EU H2020 projects IPERION HS and APACHE (GA 814496). The development of the app was carried out by the Heritage Science Lab Ljubljana (University of Ljubljana) and UCL Institute for Sustainable Heritage, in collaboration with the Smithsonian Institution’s Museum Conservation Institute.