Comparison of Storage Systems for a Scientific-Technical Museum Collection Based on Corrosivity Assessment by Metallic Dosimeters

A good storage system is crucial for the preservation of a museum's artefacts. The choice of these systems depends largely on the nature of the collection, in particular the materials and size of the artefacts, but also other external constraints such as the financial resources of the museum. Proper environmental monitoring and understanding how it impacts the conservation of materials are essential for implementing effective preventive conservation measures. This study examines the storage environment and the suitability of the storage systems of the National Museum of Science and Technology (MUNCYT) in Madrid (Spain) from the conservation point of view. For this purpose, metallic coupons were placed inside and outside a closed mobile shelving system and wrapped and unwrapped in a tissue used for large artefacts in an open pallet racking area. The corrosion of the coupons was evaluated in terms of corrosion rate by gravimetry and electrolytic cathodic reduction according to ISO 11844:2020, colour changes were analysed with a spectrophotometer, and the corrosion products formed were characterised by XRD in grazing incidence mode. The results enabled a comparison of the corrosiveness in different areas, identification of possible sources of aggressive pollutants, and demonstrated the effectiveness of storing artefacts inside shelving and tissue wrapping in reducing metal degradation (especially silver) of the artefacts in the MUNCYT collection.