In the field of built environment assessing and monitoring, it is generally agreed that control of the air quality is vital to the protection of the valuable, culturally-significant objects in museums, expositions, depositories, and archives. The main factors affecting air corrosiveness are temperature, relative humidity, the concentration of pollutants such as SO2, NOx, O3, NH3, HCl, H2S, dispersed chlorides, organic acids, other volatile compounds and dust particles.
Usually, only the relative humidity and temperature are controlled and monitored. Additional anti-corrosion measures may be applied after valuable and often irreplaceable historical objects have already been affected. Since control of the air without the application of any monitoring technique to give rapid feedback on the air quality might be either inadequate or excessive, and thus too costly, information on the actual corrosiveness of the atmosphere is crucial for effective corrosion protection.
In a project financed within FP6, prototypes of loggers were developed for continuous measurement of the corrosion rate of selected technical metals in atmospheric conditions. MUSECORR project, financed within FP7_ENV and coordinated by Institut de la Corrosion, completes the previous development by adjusting the prototypes for application in the highly demanding cultural heritage sphere.
AirCorr loggers are based on electronic units which measure and record changes in the electrical resistance of a thin metal track applied on an insulating substrate. If the metal corrodes, the electrical resistance increases. A part of the metal track is protected by an organic coating and, thus, serves as a reference to compensate for resistivity changes due to varying temperature. Three versions of the AirCorr logger have been designed for specific applications: indoor, indoor with two corrosion sensors and temperature and humidity recording, and watertight outdoor. The devices have a reduced size, easily replaceable sensors, quick response time, high sensitivity, user friendly software and remote data access or autonomous mode. The envisaged use is monitoring the corrosiveness of climates and microclimates in museums and depositories, which can be useful for assessing potential deterioration of metallic objects. The potential corrosion of other materials like wood, paper, textile, leather, ceramic, glass, plastic etc., can be also determined.
Having passed full-scale end-users tests by April 2012, the AirCorr loggers are ready for market uptake: production guide/plan and estimated market price already available. Thus, the Technology Readiness Level reaches a level 9 on the TRL scale. The exploitation rights belong to two companies and Institut de la Corrosion will lead the way towards commercialization, intended for the second half of 2012. They would be interested in going into partnership with a commercial firm or an investor who would help with the marketing and with the large scale production. The main application targets are in the field of assessing and monitoring indoor environments, in particular in cultural heritage institutions as it has already been demonstrated that AirCorr loggers meet a real necessity of museums. Additional potential application fields are in the automotive industry, marine transport and computer rooms.