in situ damage assessment of microclimates for cultural heritage preservation marianne odlyha...
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In Situ Damage Assessment of Microclimates for Cultural Heritage Preservation
Marianne Odlyha
Thermal Methods & Conservation Science
Birkbeck College, University of London
Indoor Air Quality in Museumsand Historic Properties
6th INTERNATIONAL CONFERENCE
10-12 November 2004CNR-Padova
Topic : Innovative and existing tools to monitor the environment in museums (or microclimate of art objects) and the damage on art objects.
Microclimate Indoor Monitoring in Cultural Heritage Preservation MIMIC
http://iaq.dk/mimic
EC 5th framework : Subsection 4.2.1
Improved damage assessment of cultural heritage
Microclimate Indoor Monitoring in Cultural Heritage Preservation MIMIC (EVK4-2000-00040)
Alcázar Segovia Cord room National Museum Denmark Room 134
EC Scientific Officer responsible: Dr.Johanna LeissnerEC Scientific Officer responsible: Dr.Johanna Leissner
Innovative tool based on piezoelectric quartz crystal technology exposed in Charlottenborg Castle, Copenhagen
22cmx14cm
7cm x 5cm
QTS-3
Design of QTS-3 system
Incorporates reference crystal (uncoated) so that the output signal is a frequency difference and gives the actual coating frequency or loading on the crystal. This will be referred to as F (kHz)
Measured damage is then calculated from the change in the value of F (kHz) referred to as f (Hz) and expressed as a ratio (f/F) ie change in Hz per kHz of coating.
Time Count 1 Count 2 Count 3 Count 4 Count 5 Count 6 Count 7 Count 80.00 761.00 16438.00 17040.00 17427.00 16233.00 18560.00 18972.00 19386.00
3600.10 762.00 16440.00 17043.00 17429.00 16234.00 18562.00 18972.00 19390.007200.10 767.00 16445.00 17048.00 17436.00 16240.00 18565.00 18978.00 19391.00
1. Example of data
-5
0
5
10
15
20
25
0 10 20 30 40 50
2. Example of processed data: calculate f (change in frequency) / F (frequency at time =0secs). F is the loading on the crystal
Uncoated crystal
Coated crystals
Petrie Museum, London
Days
End-users
English Heritage
Rangers
after E1
(10.03.04-10.05.04)
61 days
f/F(RM) =16
c.f Chiswick
RM(f/F) =25
4 35.00 1.475 35.00 3.34
4 70.00 6.475 70.00 7.06
4 125 7.995 125 8.1
4 162 9.025 162 9.24
4 189 8.695 189 8.75
Crystal posn Days f/F
Exposure in British Library
17.02.04 to 5.10.04
Processing of Climate data
Climate data from selected sites (Southern Europe), & (Northern Europe) have been compiled in one large climate data file: Grand Unified MIMIC Data Base “GUMD”.
GUMD, and related data, are all available on the MIMIC website. http://iaq.dk/mimic.
For data reduction we record the number of times T & RH values exceed certain limits as a preparation for calculating risk factors.
Light dosage (luxh) is calculated for each exposure period.
Pollution dosage is also calculated (g/m3h).
Processing of climate data (National Museum of Denmark) & pollutant levels NMD Room 134
PQC array Start date End date No. Days24/07/2002 02/09/2002 40
T_av T_max T_min26.8 30.2 22.1
T variations T variations T variations T variations T variations0,0-2,0C 2,1-4,0C 4,1-6,0C 6,1-8,0C >8,0C
9 30 1 0 0
RH_av RH_max RH_min49.5 62.4 32.0
RH variations RH variations RH variations RH variations RH variations RH variations0,0-5,0% 5,1-10,0% 10,1-15,0% 15,1-20,0% 20,1-25,0% >25,0%
5 18 12 3 2 0
TWPI Lightdose (kluxhrs)19 22.1
Dose SO2 Dose O3 Dose NO2 Dose NOx Dose HNO2 Dose HNO3
736.8 4281.6 13473.6 28492.8 7490.4 3055.2
NMD after 2 exposures in Rm 134 (July - Sept 2002)
E1= 30 days
E2= 40 days
Ecum=70 days
02
46
81012
1416
1820
M2E1
M2E2
M4E1
M4E2
M7E1
M7E2
0
5
10
15
20
25
30
M2
E1
M2
E2
M4
E1
M4
E2
M7
E1
M7
E2
M5
E1
V
M6
E1
V
M7
E1
VM2E1
M2E2
M4E1
M4E2
M7E1
M7E2
M5E1 V
M6E1 V
M7E1 V
Response (f/F)
resin mastic coated crystals in positions 2, 4and 7
RM response NMD134
NMD134
Vestibule
Passive sampler dosimeters interrogated at monthly intervals
Includes one exposure in Vestibule
Response PQC (f/F) vs no. of exposures
Processing of climate data (National Museum of Denmark) & pollutant levels NMD Vestibule
PQC array Start date End date No. Days2/07/2002 12/08/2002 40
T_av T_max T_min27.2 31.4 23.7
T variations T variations T variations T variations T variations0,0-2,0C 2,1-4,0C 4,1-6,0C 6,1-8,0C >8,0C
9 29 2 0 0
RH_av RH_max RH_min42.8 57.1 25.5
RH variations RH variations RH variations RH variations RH variations RH variations0,0-5,0% 5,1-10,0% 10,1-15,0% 15,1-20,0% 20,1-25,0% >25,0%
1 20 17 2 0 0
TWPI Lightdose (kluxhrs)22 4303700
Dose SO2 Dose O3 Dose NO2 Dose NOx Dose HNO2 Dose HNO3
768 12192 21984 24288 1632 7872
Thermokinetics (Advanced kinetic calculations)
Effect of temperature modulations of sample maintained at 40
(+/- 40C) for 1 year
http://www.akts.com
Compare light and pollutant dosages received in NMD (134) and NMD Vestibule much higher light dosage
higher ozone dosage
lower NO2
higher HNO3
and much higher f/F
-1
0
1
2
3
4
5
6
7
8
9
0 5 10 15 20
RM2
RM3
RM4
RM5
RM6
RM7
Calibration: Effect of long exposure (14hrs at 10ppm) NO2 on resin mastic coated crystals positions 2,3 and 4 exposed
Gas on
Gas off
(f/F) vs hrs of exposure
Exposure 10ppm 12 hrs gives same response as 20ppm for 6 hrs
Calibration (f/F) vs Dosage (ppm hrs)
-2
0
2
4
6
8
10
0 50 100 150 200
Petrie 29.7 ppm hrs (1month)
NMD V 11.57 ppm hrs(1month)
NO2 ppm hrs
-3-2-101234567
0 20000 40000 60000 80000 100000
Calibration : Modulated RH (50%70% 50% 30% 50% ) imposed on resin mastic coated crystal exposed to NO2
Site information from FTIR data: example of strip frame data for egg tempera strips exposed at Osterley Manor
SITE Control Up Down Days CIS CO
Osterley Manor SF1 27.09.02 07.11.02 5.12.02 28.00 0.95 1.29Osterley Manor SF1 27.09.02 07.11.02 5.12.02 28.00 0.95 1.37Osterley Manor SF1 27.09.02 07.11.02 5.12.02 28.00 0.95 1.38
Osterley Manor SF1 27.09.02 06.01.03 06.02.03 60.00 0.84 2.28Osterley Manor SF1 27.09.02 06.01.03 06.02.03 60.00 0.84 2.12Osterley Manor SF1 27.09.02 06.01.03 06.02.03 60.00 0.84 2.29
Similar table with exposures for the same period but giving f/F values for the sites
Multiple external reflectance
with the Dura AmplirIR
FTIR
1850 1800 1750 1700 1650 1600 1550
Wavenumber (cm-1)
FTIR Mastic Blue=Isle of Wight(direct sunlight 12 hrs) Red=Chiswick (70 days, f/F= 25) Purple=040304 Control, Black=British Library (after 189 days, f/F = 8.8)
Climate data reduction expressed in terms of TWPI values for the duration of dosimeter exposure.
14C, 40%RH = 124 Years
20C, 50%RH = 44 Years (heat for human comfort lowers TWPI)
28C, 70%RH = 10 Years
In MIMIC British Library most controlled site and for periods of dosimeter exposure
Damage values are registered by coatings are low. Indoor pollutant levels are also lowest of the sites. TWPI values are low (c.30-40)
MIMIC dosimeters together with TWPI values describe more realistically the quality of the environment.
Conclusions
Summer
NMD 134 June 2002 TWPI 27 ALC MM 45 ALC Cord 54
NMD 134 July 2002 TWPI 19 ALC MM 36 ALC Cord 34
TWPI decreases, dosimeter damage values increase (pollutants ALC MM increase in O3 , NMD increase in NOx)
Winter
SAC Oct-Nov 2002 TWPI 50
SAC Jan-Feb 2003 TWPI 91
TWPI increases, dosimeter damage increases, and pollutant dosage NOx increases
Charlottenborg Castle (TWPI 97) has lower level of pollutant dosage NOx and lower level of dosimeter damage.
Conclusions
Benefits MIMIC project
Small portable system which can be exposed for 1-3months either as passive sampler or continuously recording. It will incorporate RH,T sensor. Option of telemetry link will be possible.
Optional small palette with similar coating (egg tempera, varnish). Readily analysed by FTIR.
Possible use for screening damage during transport of works of art (Meeting organised by SIT,Madrid,Nov 2003)
Database of damage values obtained at monitored sites (delta f/F) and chemical data (FTIR) .
Database of damage values obtained from accelerated ageing.
.
Acknowledgements
EC 5th Framework DGXII “Protection & Conservation of European Cultural
Heritage””.for funding the MIMIC project
Nancy Wade, paintings conservator University of London , Birkbeck College, Dr.J.Slater Dr. M.Appleton (QuartzTec)Dr.Q.Wang, R.Campana, Dr. A.Beard, and C.F.WilsonUniversity College, Dr.K.Pratt (UCL Chem)CNR- Istituto Inquinamento Atmosferico & IROE-CNR, Dr.F. de Santis, Dr.M.Bacci, Dr.M.Picollo, CNR-Rome and Florence,ItalyEl Alcázar,Segovia,Spain, Victoria Smith. National Trust, U.K., Linda Bullock ,National Museum of Denmark, Copenhagen, Morten Ryhl-Svendsen, Dr.Tim Padfield, and Lars Aasbjerg JensenFOM Institute (Netherlands) Prof. J.J.Boon & Dr. E.FerrairaTate Britain Conservation Dept.,Dr.B.Ormsby,Stephen Hackney & Dr.J.H.TownsendWinnats Scientific Services Dr.R.West, XPS analysisEnglish Heritage David ThickettBritish Library K.Matsuoka
Compare light and pollutant dosages received in NMD (134) and NMD Vestibule much higher light dosage
Higher ozone dosage
Lower NO2
Higher HNO3
And much higher f/F
Time Count 1 Count 2 Count 3 Count 4 Count 5 Count 6 Count 7 Count 8uncoated egg egg resin mastic resin mastic resin masticuncoated uncoated
0.00 705 11303 11601 12926 17882 17776 719 6897200.20 714 11357 11657 12891 17900 17808 722 698
delta f 9 54 56 -35 18 32 3 9f/F 4.78 4.83 -2.71 1.01 1.80
737 11458 11780 12790 18054 17919 759 734delta f 32 155 179 -136 172 143 40 45f/F 13.71 15.43 -10.52 9.62 8.04
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