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James Crawford

  Welcome to this introduction to my research with Analytical Science Projects (ASP) in the University of Warwick’s Department of Physics.  
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Making a contribution to the preservation of cultural heritage is the overriding objective of my thesis; to this end I formed an industrial collaboration between the University and ClickNetherfield, a major conservation display case manufacturer in the United Kingdom.    

Stable microclimates as sustainable solutions for preserving cultural heritage artefacts

Upgrading the passive display case

Prevention is better than cure: it has long been known that microclimates made of benign atmospheres provide ideal environments to safeguard cultural heritage artefacts for future generations. Passive display cases are less costly and consume less energy than active ones: with electric-powered environmental conditioning. Knowledge of how air is transported to and from display case interiors is fundamental to the preservation of significant and vulnerable cultural heritage artefacts worthy of display. Studying air exchange mechanisms of commercially available passive displays loaned by ClickNetherfield Ltd is underway with the aim of controlling this air exchange.
rathgen
potential air ingression  display case
An "air-tight" display case in the 1932 English translation of F. Rathgen's "The Preservation of Antiquities. A Handbook for Curators" (1905) Some of the components from the external atmosphere which eventually penetrate display cases

A case with its vertically-hinged door - a popular configuration for heritage collections, but is susceptible to "stack effect" (image: ClickNetherfield Ltd)


By controlling airtightness according to the conservation needs of the exhibits, display cases can be filtered or ventilated in a regulated manner. Engineering the airtightness of cases is key, and to measure this parameter two methods are being used:


  1. Measurement of the dilution of a tracer gas (CO2 added to an elevated concentration) over time, and
  2. Measurement of the positive or negative pressure differentials caused by the measured airflow into (i.e. pressurisation) or out of (i.e. depressurisation) cases.
testchamber.jpg

12_hourly_heating_47pcnt.gif

An orthographic-view (main) and plan perspective (overlay) of the 20 m3 thermally-stable test-room with two display cases and the distribution of environment and tracer gas sensors

Under test: a 1 m3 industry-produced display case with unframed door

Effects on air exchange caused by the ambient environment, not just the sealing quality of a display case, are recognised. So environmental simulations in a temperature-stable (±0.05 °C day-1) room are being undertaken while monitoring the interiors and exteriors of the cases for temperature, pressure and relative humidity.

tracer gas decay data
Evaluating case airtightness prototypes by the tracer gas decay method while cycling temperature
James Crawford

James Crawford BAppSc (Cons. Cult. Mats.) MCons (App. Cons.) MPhil (Phys.)

Supervisors

Prof Mark Dowsett University of Warwick

Prof Annemie Adriaens Universiteit Gent

Advisor

David Thickett English Heritage

Collaborators & funders

  cn_logo_vertical_50x274 

warwick uni blue 56x145

englishheritage_logo143x50Herbert Art Gallery & Museum Coventry

Warwick Ventures Ltd

Contacts

jamesbcrawford76 at gmail dot com
J dot B dot Crawford at warwick dot ac dot uk
 
Tel: +44 (0)24765 72840
Mob: +44 (0)7514 807 366
Fax: +44 (0)24761 50897
Skype: james.b.crawford
 
Department of Physics
University of Warwick
Gibbet Hill Road
Coventry CV4 7AL
UNITED KINGDOM