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Table 3-3: Artefact dimensions.

Table 3 -3: Artefact dimensions.

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Examples of passive diffusion gas samplers for a) A range of gases depending on preparation of absorbing medium. b) Volatile Organic Compounds (VOCs) and c) Formaldehyde.
Examples of passive diffusion gas samplers for a) A range of gases depending on preparation of absorbing medium. b) Volatile Organic Compounds (VOCs) and c) Formaldehyde.
The main dosimeters used in the PROPAINT project: A. The NILU EWO (Early Warning dosimeter for Organic materials). B. The Birkbeck PQC (Piezoelectric Quartz Crystal) dosimeter and C. The Fraunhofer ISC GSD (Glass Slide Dosimeter). Dosimetry can be thought of as the inverse of parameter monitoring. In parameter monitoring the potential for deterioration is inferred from environmental measurement. We assume we are measuring all the relevant parameters and may have to employ a range of techniques to do so. In dosimetry some form of sacrificial material that responds similarly to the materials of interest is exposed to the environment, and from its deterioration, the quality of the environment is inferred. Dosimetry has the advantage that a generic and synergistic integrated effect of all or a part of the different environmental factors (parameters) present in the environment (e.g. climate, light, pollutants) is usually measured.
The main dosimeters used in the PROPAINT project: A. The NILU EWO (Early Warning dosimeter for Organic materials). B. The Birkbeck PQC (Piezoelectric Quartz Crystal) dosimeter and C. The Fraunhofer ISC GSD (Glass Slide Dosimeter). Dosimetry can be thought of as the inverse of parameter monitoring. In parameter monitoring the potential for deterioration is inferred from environmental measurement. We assume we are measuring all the relevant parameters and may have to employ a range of techniques to do so. In dosimetry some form of sacrificial material that responds similarly to the materials of interest is exposed to the environment, and from its deterioration, the quality of the environment is inferred. Dosimetry has the advantage that a generic and synergistic integrated effect of all or a part of the different environmental factors (parameters) present in the environment (e.g. climate, light, pollutants) is usually measured.
5: The EWO dosimeter developed at NILU, exposed at Statens Museum for Kunst, Copenhagen, DK. Upper Right; the holder for up to four dosimeters, below the miniaturised holder for one dosimeter. In the EC funded project MASTER (2003-2006; MASTER project, 2009) an Early Warning dosimeter for Organic materials (EWO) was developed by the Norwegian Institute for Ait Research (NILU), (Figure 4A and Figure 5). The EWO dosimeter is a synthetic polymer sensitive to NO2 and O3, and to SO2 only at high humidity and concentrations, usually emitted outdoors and ventilated or infiltrating to the indoors. It is also sensitive to the climate parameters of temperature and UV light, and it has indirectly been calibrated for RH using RH - T isoperm values (Sebera, 1994). The effects of the environment on the EWO dosimete1 was initially measured in 120 periods of 3 months, in 30 locations in 10 European museums, during one year campaign in the EU project MASTER (Grentoft et al., 2006). Calibration of the dosimeter response against the environmental influences has also been performed. Further, evaluation of tolerable response levels for the EWO, as compared to effects on organic cultural heritage objects, was performed. The evaluation was based on reported degradation impacts of single environmental parameters on heritage objects (Tétreault, 2003) and suggested environmental standards for indoor cultural heritage locations as reported in the literature (ASHRAE, 2007). Tolerable impact levels were suggested for indoor cultural heritage locations with different degree of protection against the outdoors, ranging from archives to outside stores with no control (Figure 6). Tolerable response levels for showcases were set to one level lower than the indoor location.
5: The EWO dosimeter developed at NILU, exposed at Statens Museum for Kunst, Copenhagen, DK. Upper Right; the holder for up to four dosimeters, below the miniaturised holder for one dosimeter. In the EC funded project MASTER (2003-2006; MASTER project, 2009) an Early Warning dosimeter for Organic materials (EWO) was developed by the Norwegian Institute for Ait Research (NILU), (Figure 4A and Figure 5). The EWO dosimeter is a synthetic polymer sensitive to NO2 and O3, and to SO2 only at high humidity and concentrations, usually emitted outdoors and ventilated or infiltrating to the indoors. It is also sensitive to the climate parameters of temperature and UV light, and it has indirectly been calibrated for RH using RH - T isoperm values (Sebera, 1994). The effects of the environment on the EWO dosimete1 was initially measured in 120 periods of 3 months, in 30 locations in 10 European museums, during one year campaign in the EU project MASTER (Grentoft et al., 2006). Calibration of the dosimeter response against the environmental influences has also been performed. Further, evaluation of tolerable response levels for the EWO, as compared to effects on organic cultural heritage objects, was performed. The evaluation was based on reported degradation impacts of single environmental parameters on heritage objects (Tétreault, 2003) and suggested environmental standards for indoor cultural heritage locations as reported in the literature (ASHRAE, 2007). Tolerable impact levels were suggested for indoor cultural heritage locations with different degree of protection against the outdoors, ranging from archives to outside stores with no control (Figure 6). Tolerable response levels for showcases were set to one level lower than the indoor location.
re 6: Table for interpretation of environmental quality for cultural heritage in different locations based on EWO dosimeter results. (Grentoft et al., 2006).
re 6: Table for interpretation of environmental quality for cultural heritage in different locations based on EWO dosimeter results. (Grentoft et al., 2006).
re 7: The PQC dosimeters for continuous operation, developed by Birkbeck, exposed at Statens Museum for Kunst, Copenhagen, DK. eight PQC-dosimeter crystals (four RM-PQC and four L-PQC), two to four crystals clamped between steel plates were suspended within the microclimate frames. The frequency shift for the PQCs was measured before and after the exposures, and was calculated as the % change in frequency or (Hz/kHz) shift in frequency. L-PQC values are only compared between themselves, as are RM-PQC values, and the different units can be compared to results in Odlyha et al. (2005) and SENSORGAN (2009). High values of change correlated with the presence of high levels of photo-oxidising agents (RM-PQC crystals) and high levels of volatile organic acids (L-PQC). A new miniaturised prototype for measuring the frequency shift of the crystals in real time has been developed within the PROPAINT project for use within the restricted environment of the microclimate frames (Figure 7). 3.3.2.4 The Glass Slide Dosimeter
re 7: The PQC dosimeters for continuous operation, developed by Birkbeck, exposed at Statens Museum for Kunst, Copenhagen, DK. eight PQC-dosimeter crystals (four RM-PQC and four L-PQC), two to four crystals clamped between steel plates were suspended within the microclimate frames. The frequency shift for the PQCs was measured before and after the exposures, and was calculated as the % change in frequency or (Hz/kHz) shift in frequency. L-PQC values are only compared between themselves, as are RM-PQC values, and the different units can be compared to results in Odlyha et al. (2005) and SENSORGAN (2009). High values of change correlated with the presence of high levels of photo-oxidising agents (RM-PQC crystals) and high levels of volatile organic acids (L-PQC). A new miniaturised prototype for measuring the frequency shift of the crystals in real time has been developed within the PROPAINT project for use within the restricted environment of the microclimate frames (Figure 7). 3.3.2.4 The Glass Slide Dosimeter
Figure 8: The Glass Slide Dosimeter developed by Fraunhofer ISC, exposed at the National Museum in Krakow, Poland. treatments, MI, M2, and M5), were exposed. The dosimeter type that was found to be best suited for indoor museum room and showcase measurements over the last 15 years (M1.0 with fire polishing finish), and showed the best sensitivity and linear behaviour, was used in PROPAINT.
Figure 8: The Glass Slide Dosimeter developed by Fraunhofer ISC, exposed at the National Museum in Krakow, Poland. treatments, MI, M2, and M5), were exposed. The dosimeter type that was found to be best suited for indoor museum room and showcase measurements over the last 15 years (M1.0 with fire polishing finish), and showed the best sensitivity and linear behaviour, was used in PROPAINT.
Environmental Glass Slide Dosimeters (type M1.0 and MI): range of exposure results (4E-values) and related evaluation criteria after 3 month exposure (see also Figure 14). In Figure 9, the range of possible and observed Glass Dosimeter results (AE-values) ar shown together with related evaluation criteria for environmental risk potential regardin: artworks.
Environmental Glass Slide Dosimeters (type M1.0 and MI): range of exposure results (4E-values) and related evaluation criteria after 3 month exposure (see also Figure 14). In Figure 9, the range of possible and observed Glass Dosimeter results (AE-values) ar shown together with related evaluation criteria for environmental risk potential regardin: artworks.
igure 10: Environmental Glass Slide Dosimeters: correlation of AE-values (3 months exposure) after acetic acid exposure vs. acetic acid concentration (all available data).
igure 10: Environmental Glass Slide Dosimeters: correlation of AE-values (3 months exposure) after acetic acid exposure vs. acetic acid concentration (all available data).
The locations for exposures in microclimate frames in PROPAINT fable 3: The locations for exposures in microclimate frames in PROPAINT * M = “Modern” new built. H = “Historic” modified. O = Open microclimate enclosure. **Glass in microclimate frames and rooms is not included. (-) = not available. ~ Measurements were also performed in a showcase in the Uffizi, Italy and in a storeroom Japan (Figure 12).
The locations for exposures in microclimate frames in PROPAINT fable 3: The locations for exposures in microclimate frames in PROPAINT * M = “Modern” new built. H = “Historic” modified. O = Open microclimate enclosure. **Glass in microclimate frames and rooms is not included. (-) = not available. ~ Measurements were also performed in a showcase in the Uffizi, Italy and in a storeroom Japan (Figure 12).
yure 11: Three dosimeters: 1. Early Warning Organic (EWO) dosimeter 2. Resin Mastic (RM-PQC) and Lead Piezoelectric Quartz Crystal (L-PQC) and 3. The Glass Slide Dosimeter (GSD), mounted inside the “modern” SIT-Artyd microclimate frame (A) and a “historic” frame adapted to microclimate frame at English Heritage, Apsley House, London, UK (B). C: Glass enclosure for painting (National Museum in Krakow). D: Showcase (Uffizi Gallery). Two general types of microclimate frame designs were tested: “Modern” new microclimate frames purpose built by the SIT-Artyd Company and “historical” microclimate frames adapted to existing picture frames (Figure 11 and Table 3). In location no. 12 (Table 3) the painting was placed in a more open purpose built glass enclosure with glass (front and sides) fitted to the wall (Figure 11C). Measurements were also performed in a showcase located in the Uffizi Gallery, Florence, Italy (Figure 11D).
yure 11: Three dosimeters: 1. Early Warning Organic (EWO) dosimeter 2. Resin Mastic (RM-PQC) and Lead Piezoelectric Quartz Crystal (L-PQC) and 3. The Glass Slide Dosimeter (GSD), mounted inside the “modern” SIT-Artyd microclimate frame (A) and a “historic” frame adapted to microclimate frame at English Heritage, Apsley House, London, UK (B). C: Glass enclosure for painting (National Museum in Krakow). D: Showcase (Uffizi Gallery). Two general types of microclimate frame designs were tested: “Modern” new microclimate frames purpose built by the SIT-Artyd Company and “historical” microclimate frames adapted to existing picture frames (Figure 11 and Table 3). In location no. 12 (Table 3) the painting was placed in a more open purpose built glass enclosure with glass (front and sides) fitted to the wall (Figure 11C). Measurements were also performed in a showcase located in the Uffizi Gallery, Florence, Italy (Figure 11D).
Figure 12 shows exposure locations in the end-user institutions. The measurements in PROPAINT were divided between a general measurement campaign and different case studies. In addition to the dosimeters, passive diffusion gas samplers and climate measurements, the air exchange rates of the microclimate frames were measured in the general campaign. The general measurement campaign included all locations (Table 3). The case studies focused on specific concerns and were carried out at selected locations (see Chapter 4.6). (Results for four additional frames located in the SIT workshop are given in Appendix 1).
Figure 12 shows exposure locations in the end-user institutions. The measurements in PROPAINT were divided between a general measurement campaign and different case studies. In addition to the dosimeters, passive diffusion gas samplers and climate measurements, the air exchange rates of the microclimate frames were measured in the general campaign. The general measurement campaign included all locations (Table 3). The case studies focused on specific concerns and were carried out at selected locations (see Chapter 4.6). (Results for four additional frames located in the SIT workshop are given in Appendix 1).
Figure 13: The Dosimeters placed outside the microclimate frame with a painting made by Edvard Munch, Nasjonalmuseet for Kunst, Arkitektur og Design, Oslo, Norway.
Figure 13: The Dosimeters placed outside the microclimate frame with a painting made by Edvard Munch, Nasjonalmuseet for Kunst, Arkitektur og Design, Oslo, Norway.
4 Dosimeter results obtained inside and outside microclimate frames for paintings with (A): The Resin Mastic POC dosimeter (f/ F, = relation between the frequency shift and the original coated crystal frequency, KHz). For SMK2 measurement was not performed outside the microclimate frame. The standard deviation for the measurements ranged from 0.66 to 1.0 with unit 1000*f/Fo. (B): the Lead PQC dosimeter (Change (%) in frequency or mass). In the case of SMK2, EH.K and SIT-Artyd, measurements with L-PQCs were not performed in the rooms. For the other rooms no response was detected. The standard deviation for the measurements of the L-PQCs ranged from 0.12 to 0.22 %. (C): The EWO dosimeter (average of two parallel exposures, except in GNM room. The EWO response is in absorption units at 340 nm). SMK = SMK1. Number in brackets are tolerability location levels [11] (at RH = 55%): [1]: Archive store, [2]: Purpose built Museum Gallery, [3]: Historic House Museum, [4]: Open display in open museum, [5]: Outside store with no control. (D): The Glass Slide Dosimeter. (AE - Extinction values measured as IR absorption at 3300 cm"). (SMK = SMK1, “Rubens frame” = SMK2).
4 Dosimeter results obtained inside and outside microclimate frames for paintings with (A): The Resin Mastic POC dosimeter (f/ F, = relation between the frequency shift and the original coated crystal frequency, KHz). For SMK2 measurement was not performed outside the microclimate frame. The standard deviation for the measurements ranged from 0.66 to 1.0 with unit 1000*f/Fo. (B): the Lead PQC dosimeter (Change (%) in frequency or mass). In the case of SMK2, EH.K and SIT-Artyd, measurements with L-PQCs were not performed in the rooms. For the other rooms no response was detected. The standard deviation for the measurements of the L-PQCs ranged from 0.12 to 0.22 %. (C): The EWO dosimeter (average of two parallel exposures, except in GNM room. The EWO response is in absorption units at 340 nm). SMK = SMK1. Number in brackets are tolerability location levels [11] (at RH = 55%): [1]: Archive store, [2]: Purpose built Museum Gallery, [3]: Historic House Museum, [4]: Open display in open museum, [5]: Outside store with no control. (D): The Glass Slide Dosimeter. (AE - Extinction values measured as IR absorption at 3300 cm"). (SMK = SMK1, “Rubens frame” = SMK2).
gure 15: Results from exposures of the EWO, GSD. L-PQCs and RM-PQCs inside and outside the SMK2 microclimate frame (Table 23). The units for the L-PQC and RM-PQC are % change and 1000*f/F (= relation between the frequency shift and the original coated crystal frequency), respectively.
gure 15: Results from exposures of the EWO, GSD. L-PQCs and RM-PQCs inside and outside the SMK2 microclimate frame (Table 23). The units for the L-PQC and RM-PQC are % change and 1000*f/F (= relation between the frequency shift and the original coated crystal frequency), respectively.
Figure 18: Concentrations of NO2 and O3 measured inside and outside microclimate frames. For location abbreviations see Table 3 and table in Figure text 12. Sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), organic acids (acetic and formic acids), formaldehyde and VOCs (Volatile Organic Compounds) were measured. Inorganic gases, such as NO, SO and Os, are formed mainly outdoors and infiltrates to the indoor environment, and into microclimate frames. NO2 and 03 were measured inside nearly all the microclimate frames, varying between 1 and 5 pg m®, and 1 and 7 pg m°®, respectively (Figure 18). SO2 concentrations inside microclimate frames were generally very low (<0.5 pg my’).
Figure 18: Concentrations of NO2 and O3 measured inside and outside microclimate frames. For location abbreviations see Table 3 and table in Figure text 12. Sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), organic acids (acetic and formic acids), formaldehyde and VOCs (Volatile Organic Compounds) were measured. Inorganic gases, such as NO, SO and Os, are formed mainly outdoors and infiltrates to the indoor environment, and into microclimate frames. NO2 and 03 were measured inside nearly all the microclimate frames, varying between 1 and 5 pg m®, and 1 and 7 pg m°®, respectively (Figure 18). SO2 concentrations inside microclimate frames were generally very low (<0.5 pg my’).
Figure 17: Correlation between dosimeter responses in microclimate frames and rooms. A: EWO and RM-PQC with locations tolerability levels (Figure 14C and A). B: GSD and L-PQC with impact levels (Figure 14D and Figure 15B).
Figure 17: Correlation between dosimeter responses in microclimate frames and rooms. A: EWO and RM-PQC with locations tolerability levels (Figure 14C and A). B: GSD and L-PQC with impact levels (Figure 14D and Figure 15B).
Figure 19: Total concentration of volatile organic compounds (TVOC), acetic acid, formic acid and formaldehyde measured inside and outside microclimate frames. For location abbreviations see Table 3 and table in Figure text 12. compounds are emitted by materials commonly used in the construction of microclimate frames and from the objects inside the frames. Measurements inside the microclimate frames showed acetic acid concentrations varying from 30 to 2000 ug m™®, formic acid between 3( an 500 pg m®, formaldehydes between 1 and 6 pg m® and TVOC between 100 and 5000 pc m’? (Figure 19).
Figure 19: Total concentration of volatile organic compounds (TVOC), acetic acid, formic acid and formaldehyde measured inside and outside microclimate frames. For location abbreviations see Table 3 and table in Figure text 12. compounds are emitted by materials commonly used in the construction of microclimate frames and from the objects inside the frames. Measurements inside the microclimate frames showed acetic acid concentrations varying from 30 to 2000 ug m™®, formic acid between 3( an 500 pg m®, formaldehydes between 1 and 6 pg m® and TVOC between 100 and 5000 pc m’? (Figure 19).
Figure 21: Mean temperature measured inside and outside the microclimate frames for paintings. For location abbreviations see Table 3 and table in Figure text 12.
Figure 21: Mean temperature measured inside and outside the microclimate frames for paintings. For location abbreviations see Table 3 and table in Figure text 12.
Figure 22: Mean relative humidity measured inside and outside the microclimate frames for paintings. For location abbreviations see Table 3 and table in Figure text 12.
Figure 22: Mean relative humidity measured inside and outside the microclimate frames for paintings. For location abbreviations see Table 3 and table in Figure text 12.
| Light measurements at the sampling locations, obtained by light dosimeter (LightC heck©) and/or sensors. The dose values were normalized to 1 year dose exposure.
| Light measurements at the sampling locations, obtained by light dosimeter (LightC heck©) and/or sensors. The dose values were normalized to 1 year dose exposure.
Figure 23: Air exchange rate of PROPAINT-microclimate frames. For location abbreviations see Table 3 and table in Figure text 12.
Figure 23: Air exchange rate of PROPAINT-microclimate frames. For location abbreviations see Table 3 and table in Figure text 12.
3.6.4 Case 3: Continuous monitoring in Experimental Frame The L-PQC dosimeter with continuous recording facilities (battery operated) was set up for testing in the experimental frame prepared in the laboratories of the National Museum in Krakow (Figure 24). The frame had the following dimensions: 65 cm x 59 cm x 9.4 cm
3.6.4 Case 3: Continuous monitoring in Experimental Frame The L-PQC dosimeter with continuous recording facilities (battery operated) was set up for testing in the experimental frame prepared in the laboratories of the National Museum in Krakow (Figure 24). The frame had the following dimensions: 65 cm x 59 cm x 9.4 cm
jure 24: The position of the L-PQC dosimeter (crystals in flat silver holder) is shown using the arrow (left). The green and black traces show the change (%) in the crystals on exposure. The change occurs over the first 10/15 days. After 20 days the conditions in the microclimate chamber were changed (RH,T) (Right). Sa Ee eee ae Se Se a ee eee A a ee en a ae a es a a follows: The frame inside was secured using Aluminium foil 3M (nr 425) and it had a poly-carbonate back plate. Temperature, RH, pressure, CO2, acoustic emission and dimension sensors were also included. The frame was placed into a microclimate chamber. The strong increase in the rate of change of the L-PQC was observed after about 5 and 7 days lasting for about 5 and 15 days respectively (black and green curves in Figure 24). The total change over this period was about 12 % (Which was higher than the value (6.75 %) obtained for the English Heritage frame C (Case 2) with a similar air exchange rate and piece of oak wood (80 g) enclosed, after exposure for 3 months). After about 20 days an increase in temperature and RH seemed to cause a further change in the crystals (up to 20%) which remained a steady level despite further changes in RH and T.
jure 24: The position of the L-PQC dosimeter (crystals in flat silver holder) is shown using the arrow (left). The green and black traces show the change (%) in the crystals on exposure. The change occurs over the first 10/15 days. After 20 days the conditions in the microclimate chamber were changed (RH,T) (Right). Sa Ee eee ae Se Se a ee eee A a ee en a ae a es a a follows: The frame inside was secured using Aluminium foil 3M (nr 425) and it had a poly-carbonate back plate. Temperature, RH, pressure, CO2, acoustic emission and dimension sensors were also included. The frame was placed into a microclimate chamber. The strong increase in the rate of change of the L-PQC was observed after about 5 and 7 days lasting for about 5 and 15 days respectively (black and green curves in Figure 24). The total change over this period was about 12 % (Which was higher than the value (6.75 %) obtained for the English Heritage frame C (Case 2) with a similar air exchange rate and piece of oak wood (80 g) enclosed, after exposure for 3 months). After about 20 days an increase in temperature and RH seemed to cause a further change in the crystals (up to 20%) which remained a steady level despite further changes in RH and T.
8: Exposure of L-PQC in the back of the frame of Rossetti’s painting. In this Case Study two L-PQC crystals, a lead coupon, and an A-D strip were placed at the back of a wooden frame with oil-tempered hardboard back which was covered with thin Melinex. The painting inside the microclimate frame was Dante Gabriel Rossetti’s painting “Sancta Lilias” (Tate Store, acquisition no. N02440, oil on canvas 483 x 457 mm frame: 815 x 795 x 105 mm) (Figure 26). Table 8 gives the results from the L-PQCs.
8: Exposure of L-PQC in the back of the frame of Rossetti’s painting. In this Case Study two L-PQC crystals, a lead coupon, and an A-D strip were placed at the back of a wooden frame with oil-tempered hardboard back which was covered with thin Melinex. The painting inside the microclimate frame was Dante Gabriel Rossetti’s painting “Sancta Lilias” (Tate Store, acquisition no. N02440, oil on canvas 483 x 457 mm frame: 815 x 795 x 105 mm) (Figure 26). Table 8 gives the results from the L-PQCs.
jure 26: Back of Rossetti painting with hardboard backing removed. Top right hand corner shows crystals mounted in steel frame and top left corner shows lead coupon and A-D strip (Left). Reverse of Rossetti painting showing deposits on brass plates (Right).
jure 26: Back of Rossetti painting with hardboard backing removed. Top right hand corner shows crystals mounted in steel frame and top left corner shows lead coupon and A-D strip (Left). Reverse of Rossetti painting showing deposits on brass plates (Right).
Figure 27: Dosimeters exposed in store room of the National Research Institute for Cultura Properties, Tokyo, Japan.
Figure 27: Dosimeters exposed in store room of the National Research Institute for Cultura Properties, Tokyo, Japan.
Figure 28: EWO results at the National Research Institute for Cultural Properties, Tokyo, Japan.
Figure 28: EWO results at the National Research Institute for Cultural Properties, Tokyo, Japan.
Figure 29: Above: preparation of the varnish samples. Below: envelope containing a set of varnish samples. Figure 29 shows the preparation of the varnish samples.
Figure 29: Above: preparation of the varnish samples. Below: envelope containing a set of varnish samples. Figure 29 shows the preparation of the varnish samples.
Figure 30: The exposure chambers at NILU. Accelerated ageing of the varnish samples were carried out in the exposure chambers at NILU (Figure 30). 1.3.2 Accelerated ageing
Figure 30: The exposure chambers at NILU. Accelerated ageing of the varnish samples were carried out in the exposure chambers at NILU (Figure 30). 1.3.2 Accelerated ageing
Table 11: Sites and durations for field exposures of varnish samples in PROPAINT.
Table 11: Sites and durations for field exposures of varnish samples in PROPAINT.
Figure 31: Tate Britain, London (UK). Inside the frame. The varnish samples are exposed to light. No photos are available from outside the frame; - they were exposed to light. Figure 31 to Figure 36 show the exposure sites, also explaining if the varnish samples were exposed in the darkness or in the light.
Figure 31: Tate Britain, London (UK). Inside the frame. The varnish samples are exposed to light. No photos are available from outside the frame; - they were exposed to light. Figure 31 to Figure 36 show the exposure sites, also explaining if the varnish samples were exposed in the darkness or in the light.
Figure 33: Museo de Bellas Artes de Valencia (ES). Inside (left) and outside (right) of the frame. The varnish samples were exposed in the darkness.
Figure 33: Museo de Bellas Artes de Valencia (ES). Inside (left) and outside (right) of the frame. The varnish samples were exposed in the darkness.
Figure 34: National Museum in Krakow (PL) “Leonardo”. The varnish samples are exposed to light.
Figure 34: National Museum in Krakow (PL) “Leonardo”. The varnish samples are exposed to light.
Figure 39: Amount of free terpenoids extracted from the natural varnish samples that were exposed on site, inside and outside the frames.
Figure 39: Amount of free terpenoids extracted from the natural varnish samples that were exposed on site, inside and outside the frames.
Figure 41: Thermogravimetric graph for MS2A (continuous line) and relative derivative (dashed line).
Figure 41: Thermogravimetric graph for MS2A (continuous line) and relative derivative (dashed line).
Figure 43: Comparison of the relative amounts of monomers, dimers and macromolecular fraction evaluated as the sum of peak areas in chromatograms corresponding to the thermal desorption at 130 °C, at 250 °C and pyrolysis at 500 °C, respectively.
Figure 43: Comparison of the relative amounts of monomers, dimers and macromolecular fraction evaluated as the sum of peak areas in chromatograms corresponding to the thermal desorption at 130 °C, at 250 °C and pyrolysis at 500 °C, respectively.
Figure 44: GC-MS chromatograms of MS2A resin of the varnish sample NO2-80-59 desorbed at 130°C.
Figure 44: GC-MS chromatograms of MS2A resin of the varnish sample NO2-80-59 desorbed at 130°C.
The softening temperatures of resin mastic films on steel were measured by DMA and compared with that of the control sample. Shifts to higher temperatures indicated the formation of a more cross linked film. Highest values and evidence of a more damaging effect were observed in resin mastic films exposed to ozone at low RH (20 %). The temperature shift was about 30°C and this could be correlated with an increase in the ratio of mass fragments (523/409) in the MALDI-TOF spectra. The rationale for using this ratio was based on previous work (Scalarone, 2005) where the mass fragment at 523 was attributed to the possible formation of the oxidation product oleanic aldehyde and fragment 409 was attributed to dammardienol, the unoxidised part of the material. Figure 45 shows the effect of ozone exposure on resin mastic and the dominance of fragments in the 520 region. Figure 45: MALDI-TOF spectra for resin mastic sample exposed to an O3 dose of 117.4 ppm* day at 20 % RH.
The softening temperatures of resin mastic films on steel were measured by DMA and compared with that of the control sample. Shifts to higher temperatures indicated the formation of a more cross linked film. Highest values and evidence of a more damaging effect were observed in resin mastic films exposed to ozone at low RH (20 %). The temperature shift was about 30°C and this could be correlated with an increase in the ratio of mass fragments (523/409) in the MALDI-TOF spectra. The rationale for using this ratio was based on previous work (Scalarone, 2005) where the mass fragment at 523 was attributed to the possible formation of the oxidation product oleanic aldehyde and fragment 409 was attributed to dammardienol, the unoxidised part of the material. Figure 45 shows the effect of ozone exposure on resin mastic and the dominance of fragments in the 520 region. Figure 45: MALDI-TOF spectra for resin mastic sample exposed to an O3 dose of 117.4 ppm* day at 20 % RH.
The results obtained for the onset of softening of resin mastic films are discussed in terms of the environmental conditions, mainly the levels of inorganic and organic pollutant gases measured at the sites. The effect of ozone is most evident in the sample exposed in the museum in Mexico. Figure 46 shows values for Tg for resin mastic strips exposed in frames and in rooms. The sample in the room in the Museum in Mexico was exposed to a higher than recommended level of O3 (19.9 ug/m®) (Figure 47). The sample exposed inside the microclimate frame in Mexico city had the highest Tg value. The frame appeared not to offer any protection as the Tg in the frame was equally high as in the room (Figure 46 and Figure 49). Measurable levels of O3 (1.4 ug/m*) were present within the frame and may together with acetic acid, and light have been a contributing factor. Figure 46: Tg values for resin mastic in frames (deep red) and resin mastic in rooms (blue).
The results obtained for the onset of softening of resin mastic films are discussed in terms of the environmental conditions, mainly the levels of inorganic and organic pollutant gases measured at the sites. The effect of ozone is most evident in the sample exposed in the museum in Mexico. Figure 46 shows values for Tg for resin mastic strips exposed in frames and in rooms. The sample in the room in the Museum in Mexico was exposed to a higher than recommended level of O3 (19.9 ug/m®) (Figure 47). The sample exposed inside the microclimate frame in Mexico city had the highest Tg value. The frame appeared not to offer any protection as the Tg in the frame was equally high as in the room (Figure 46 and Figure 49). Measurable levels of O3 (1.4 ug/m*) were present within the frame and may together with acetic acid, and light have been a contributing factor. Figure 46: Tg values for resin mastic in frames (deep red) and resin mastic in rooms (blue).
Figure 48: Acetic acid concentrations i1 frames. “igure 49: Tg values of resin mastic films in frames.
Figure 48: Acetic acid concentrations i1 frames. “igure 49: Tg values of resin mastic films in frames.
Table 13: Values of Tg for accelerated aged samples of dammar and dammar and tinuvin.
Table 13: Values of Tg for accelerated aged samples of dammar and dammar and tinuvin.
igure 51: NO2 concentrations of strips in rooms.
igure 51: NO2 concentrations of strips in rooms.
Figure 52: Graph shows the plot of Tg (°C) vs. sites. IN = Inside microclimate frames. OUT = outside microclimate frames. Tg values for dammar strips exposed at the sites are shown in Figure 52.
Figure 52: Graph shows the plot of Tg (°C) vs. sites. IN = Inside microclimate frames. OUT = outside microclimate frames. Tg values for dammar strips exposed at the sites are shown in Figure 52.
Figure 55: Temperature and relative humidity recorded inside the microclimate frame for the painting “La Nana” In the Picasso Museum, Barcelona, Spain.
Figure 55: Temperature and relative humidity recorded inside the microclimate frame for the painting “La Nana” In the Picasso Museum, Barcelona, Spain.
Microclimate frame sealed (left); Front of frame (right)
Microclimate frame sealed (left); Front of frame (right)
Figure 60: Microclimate frame for “epitaph of Jan Stupecki” (section).
Figure 60: Microclimate frame for “epitaph of Jan Stupecki” (section).
mainly from traffic emissions (Mexico City, MNA, Oslo, NG, London, Tate B, and Valencia, MBV). In contrast, the pollution load inside the microclimate frames was found to be worse than for the unprotected (by the microclimate frame) room situation, in a more rural area (Germanic National Museum, GNM), for a room with good environmental control (Tate Store) and for a microclimate frame with high inside emission of organic acids (English Heritage, Kenwood). The SIT 1 microclimate frame was a test case with a specially constructed high emitting inside environment.
mainly from traffic emissions (Mexico City, MNA, Oslo, NG, London, Tate B, and Valencia, MBV). In contrast, the pollution load inside the microclimate frames was found to be worse than for the unprotected (by the microclimate frame) room situation, in a more rural area (Germanic National Museum, GNM), for a room with good environmental control (Tate Store) and for a microclimate frame with high inside emission of organic acids (English Heritage, Kenwood). The SIT 1 microclimate frame was a test case with a specially constructed high emitting inside environment.
Table 1-1: Results from the dosimeter measurement in PROPAINT.
Table 1-1: Results from the dosimeter measurement in PROPAINT.
Table 1-2: Results from the passive diffusion gas sampler measurement in PROPAINT.
Table 1-2: Results from the passive diffusion gas sampler measurement in PROPAINT.
With mockpainting and separated dosimeters. 7 With mockpainting and dosimeters together. > New empty frame. “New empty - "bad" materials. ° New empty - good" materials
With mockpainting and separated dosimeters. 7 With mockpainting and dosimeters together. > New empty frame. “New empty - "bad" materials. ° New empty - good" materials
*) at the time of PROPAINT project, c. 2008 Table 3-1: Microclimate frame characteristics
*) at the time of PROPAINT project, c. 2008 Table 3-1: Microclimate frame characteristics
Table 3-2: Microclimate frame inner dimensions.
Table 3-2: Microclimate frame inner dimensions.
Table 3-4: Total frame + artefact. Dimensions.
Table 3-4: Total frame + artefact. Dimensions.
Table 3-5: Site characteristics.
Table 3-5: Site characteristics.
Table 3-6: Room volume and air exchange.
Table 3-6: Room volume and air exchange.
reverse of the frame (fig. 1). No sorbent material is added; the buffering role of the panel is considered sufficient. A cclimatisation of the painting in the correct relative humidity is critical for the conditions in the microclimate box. Over the course of many years it has been observed by conservators in the Mauritshuis that hazy deposits regularly form on the inside of the glass. This has also been observed in other museums which glaze their paintings. These hazy deposits, often referred to as ghost- transferred- or mirror images, are disturbing and can severely obscure the art work. Often these deposits are associated with the image, hence the term mirror images (Williams 1988; Skaliks 1999). The hazy deposits are greasy in nature and depending on thickness, are greyish or whitish in appearance. In the Mauritshuis they are removed periodically by the framing technician, first with water and green soap” using a micro-fibre cloth, followed by wiping with ethanol and damp paper. Concern has developed as to the recurring nature of the deposits and the long term effect on paintings. The reoccurrence of deposits has implications for the microclimate box design and climate conditions in certain locations in the museum. Regular removal of the deposits has furthermore significantly increased the work load for the technical staff: since 2001, when cleaning of the glass began being recorded, hazy deposits on more than 200 paintings have been removed.
reverse of the frame (fig. 1). No sorbent material is added; the buffering role of the panel is considered sufficient. A cclimatisation of the painting in the correct relative humidity is critical for the conditions in the microclimate box. Over the course of many years it has been observed by conservators in the Mauritshuis that hazy deposits regularly form on the inside of the glass. This has also been observed in other museums which glaze their paintings. These hazy deposits, often referred to as ghost- transferred- or mirror images, are disturbing and can severely obscure the art work. Often these deposits are associated with the image, hence the term mirror images (Williams 1988; Skaliks 1999). The hazy deposits are greasy in nature and depending on thickness, are greyish or whitish in appearance. In the Mauritshuis they are removed periodically by the framing technician, first with water and green soap” using a micro-fibre cloth, followed by wiping with ethanol and damp paper. Concern has developed as to the recurring nature of the deposits and the long term effect on paintings. The reoccurrence of deposits has implications for the microclimate box design and climate conditions in certain locations in the museum. Regular removal of the deposits has furthermore significantly increased the work load for the technical staff: since 2001, when cleaning of the glass began being recorded, hazy deposits on more than 200 paintings have been removed.
Resultaat: Het spectrum van de aanslag op het glas vertoont absorptiebanden die overeenkomen met absorptiebanden in het referentiespectrum van natriumstearaat (een natriumcarboxylaat). Specifieke absorptiebanden in het referentiespectrum van natriumstearaat zijn: 1555 — 1469 - 1439 - 1418 - 719 - 698 cm?
Resultaat: Het spectrum van de aanslag op het glas vertoont absorptiebanden die overeenkomen met absorptiebanden in het referentiespectrum van natriumstearaat (een natriumcarboxylaat). Specifieke absorptiebanden in het referentiespectrum van natriumstearaat zijn: 1555 — 1469 - 1439 - 1418 - 719 - 698 cm?
Fig. 9. Temperature and relative humidity measurements from a test painting in microclimate box exposed to direct sunlight, 22 January 2005. (The anomalous low relative humidity of the air in the box (35%) in the lower spectrum was due to insufficient conditioning of the test painting prior to placement in the microclimate box (from Baan and Van Duijnhoven 2005, p. 51)).
Fig. 9. Temperature and relative humidity measurements from a test painting in microclimate box exposed to direct sunlight, 22 January 2005. (The anomalous low relative humidity of the air in the box (35%) in the lower spectrum was due to insufficient conditioning of the test painting prior to placement in the microclimate box (from Baan and Van Duijnhoven 2005, p. 51)).
Related topics:
ConservationCultural Heritage ConservationHeritage ConservationMuseum environment
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