| 1. |
- Dubus, Michel, et al.
(författare)
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Monitoring copper and silver corrosion in different museum environments by electrical resistance measurement
- 2010
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Ingår i: Studies in Conservation. - : Int. Inst. for Conservation of Historic and Artistic Works. - 0039-3630 .- 2047-0584. ; 55:2, s. 121-133
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Tidskriftsartikel (refereegranskat)abstract
- The results are reported of a systematic programme of electrical resistance measurement (ERM) of copper and silver corrosion rates within various museum environments, directed towards developing preventive conservation understanding and practice. Electrical resistivity measurements were made using copper and silver probes for one month and one year in 33 locations, and these are interpreted in comparison with two standards. Advantages and drawbacks of different methods available for the evaluation of the corrosion aggressiveness of indoor air are discussed. Practical solutions are proposed for improving the protection of metal objects collections. Improvements are also proposed to maximize the efficiency and suitability of the measuring device to the very specific applications of cultural heritage collections.
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| 2. |
- Kouril, Milan, et al.
(författare)
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Corrosion monitoring in archives by the electrical resistance technique
- 2014
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Ingår i: Journal of Cultural Heritage. - : Elsevier Masson SAS. - 1296-2074 .- 1778-3674. ; 15:2, s. 99-103
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Tidskriftsartikel (refereegranskat)abstract
- It is essential that corrosion monitoring of indoor atmospheres should be highly sensitive, especially, when corrosion rates corresponding to the lowest standard corrosivity categories are supposed to be identified within one or a few days. The electrical resistance technique in combination with high-sensitivity electrical resistance sensors enabled detection of a corrosion loss on an atomic scale. Case studies have demonstrated the sensors' ability to timely inform the users about changes in the atmosphere quality. In confrontation with quartz crystal microbalance technique, resistometric sensors provided better explainable data.
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| 3. |
- Prosek, Tomas, et al.
(författare)
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Application of automated corrosion sensors for real-time monitoring in atmospheres polluted with organic acids
- 2011
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Ingår i: 18th International Corrosion Congress 2011. - 9781618393630 ; , s. 1477-1484
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Konferensbidrag (refereegranskat)abstract
- Loggers for continuous measurement of the corrosion rate of metals under atmospheric conditions were developed. The electronic unit measures and records changes in the electrical resistance of a thin metal track applied on an insulating substrate. If the metal corrodes, the effective cross-sectional area of the track decreases and the electrical resistance increases. 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. Sensors made of silver, copper, iron / steel, zinc, bronze and lead with sensitivities tailored to different environments are available. Thin film metal sensors with the metal track thickness from 50 to 800 nm were made by physical vapour deposition (PVD). Examples of the logger application for continuous measurements of metal corrosion rates in air are given. Due to the sensitivity of the measurement as high as 0.1 nm, in terms of corrosion depth, changes in air corrosivity were registered within tens of minutes or hours even in low-corrosive environments. At relative humidities from 15 to 80 % and at the temperature of 20 °C, it was used for monitoring in the air polluted with controlled amounts of formic and acetic acids at concentrations from 0-1590 and 0- 870 ppb, respectively. Gases in these concentrations were reported to be found in museums and other cultural heritage institutions and are expected to cause accelerated deterioration of metal objects. Threshold limits of the formic acid concentration in air at 80 % RH and at 20 °C causing changes in the classification of indoor air corrosivity according to ISO 11844-1 are given.
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| 4. |
- Prosek, Tomas, et al.
(författare)
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Automated corrosion loggers for corrosion monitoring in the atmosphere
- 2008
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Ingår i: NACE - International Corrosion Conference Series. ; , s. 082961-082966
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Konferensbidrag (refereegranskat)abstract
- The information on actual corrosivity of the environment is crucial for efficient corrosion protection since it enables operators to take immediate counter measures against accelerating corrosion, decreasing thereby the corrosion costs. Atmospheric corrosion sensors have been developed to provide continuous measurement of the corrosion rate of steel, zinc, copper, and nickel in air. The measurement method is based on the increasing electrical resistance of a measuring element made of the material concerned as its cross sectional area diminishes due to corrosion. Data on the sensor corrosion rate are available any time without the need to retract the logger from the exposure site. They can be downloaded through the General Packet Radio Service (GPRS) connection or by means of a non-contact inductive reading. The electronic logger has dimensions of 100×65×37 mm and the weight is about 180 grams. Therefore, the logger can be placed virtually anywhere. The lifetime of the monitoring system in medium-corrosive environments is designed to be 2 years with full autonomy. Metal sensors are available at several thicknesses of metal tracks according to the anticipated level of air corrosivity and required sensitivity of measurement. Sensitivity of the corrosion measurement varies from 1 to 10 nm depending on the type and thickness of the sensor. Changes in the air corrosivity can be usually detected within several hours or even tens of minutes.
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| 5. |
- Prosek, Tomas, et al.
(författare)
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Real time corrosion monitoring in atmosphere using automated battery driven corrosion loggers
- 2008
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Ingår i: Corrosion Engineering, Science and Technology. - 1478-422X .- 1743-2782. ; 43:2, s. 129-133
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Tidskriftsartikel (refereegranskat)abstract
- A logger enabling continuous measurement of corrosion rate of selected metals in indoor and outdoor atmospheres has been developed. Principle of the measurement method is based on the increasing electrical resistance of a measuring element made of the material concerned as its cross-sectional area diminishes due to corrosion. Zinc, iron, copper and nickel sensors at several thicknesses are available. Sensitivity of the corrosion measurement varies from 1 to 10 nm depending on the type and thickness of the sensor. Changes in the air corrosivity can be thus detected within hours or even tens of minutes. The logger lifetime in medium corrosive environments is designed to be 2 years with full autonomy. Data on the sensor corrosion rate are available any time through GPRS connection or by a non-contact inductive reading without the need of retracting the logger from the exposure site.
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| 6. |
- Prosek, Tomas, et al.
(författare)
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Real-time monitoring of indoor air corrosivity in cultural heritage institutions with metallic electrical resistance sensors
- 2013
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Ingår i: Studies in Conservation. - 0039-3630 .- 2047-0584. ; 58:2, s. 117-128
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Tidskriftsartikel (refereegranskat)abstract
- A system for continuous monitoring of atmospheric corrosivity has been developed. An electronic unit measures and records changes in the electrical resistance of a thin metal track applied on an insulating substrate. If the metal corrodes, the effective cross sectional area of the track decreases and the electrical resistance increases. Sensors made of silver, copper, iron/steel, zinc, lead, tin, aluminium, bronze, and brass at thicknesses from 50 nm to 250 μm were tailored for environments with different corrosivities. The developed technology proved capable of providing high sensitivity, allowing for real-time corrosion monitoring even in low-corrosive indoor cultural heritage facilities. Laboratory tests showed good reproducibility with the standard deviation of parallel measurements at less than ±20% for metals which corrode uniformly in the tested environments. Several examples selected from a broad testing programme in partner museums, libraries, and other institutions show successful applications of the logger system for characterization of air quality control in indoor locations, during transport and in temporary exhibitions; assessment of new buildings and storage facilities; and fundamental studies of optimal conservation and storage procedures. A first outline of a classification system for lead, which is particularly sensitive to the presence of carboxylic acids, is given. The technique has a large potential as an independent method for monitoring air quality in facilities displaying and storing valuable objects of cultural heritage.
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