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