GUIDELINES FOR THE CURATION OF GEOLOGICAL MATERIALS

elative humidity, smoothing out short-time fluctuations. Cycles of rh approach
an acceptable average in good cabinets. Additionally, timber buffers against
vibration. Closed storage environments offer the possibility of emergency
treatment for material suffering from short-term humid conditions (see C2.2
Preamble). Conditioned silica gel is recommended for its buffering capacity 'which
exceeds that of timber, especially below 50% rh (Thomson 1978, Howie 1979).
2.4.2.3. Environmental monitoring
All areas where it is intended to house general collections of geological specimens
should receive occasional temperature and relative humidity checking. Where
important collections and known vulnerable specimens are stored or exhibited,
continuing monitoring is advisable. In particular, data on rh should be reliable
and the use of adequate equipment by appropriately trained operators is
necessary. Humidity sensors of the hair-hygrometer or electronic (resistivity or
capicitance) type are better than those of the coiled paper or colourimetric paper
strip type. Calibration of the hair-hygrometer types should be carried out every
few months using a wet and dry whirling or Masons hygrometer; electronic types
generally require the manufacturer to recalibrate and paper types cannot be
recalibrated. Chart recording thermo-hydrographs based on weekly or monthly
change are adequate. Special alarms may be fitted to give warning that
pre-determined high or low thresholds of rh are being exceeded.
Where the installation of an air-conditioning system is being considered, the
selection of a system to meet your requirements of temperature, rh and pollution
control should be undertaken with the specialist advice of an appropriate
consulting engineer.
.
PACKING AND TRANSPORT
The key to packing specimens is to ensure that they are firm and unable to move
within any layer of their packing. Failure to prevent vibration and movement of
specimens against one another or hard surfaces is the cause of most damage to
material in transit. Specimens should never be sent loose within a container
however well that container is packed. The best method of packing gives
three-layer protection: soft inner coccoon; rigid box for impact resistance; soft
outer wrap as shock-absorber and weather-proofer (see Stolow 1981).
Individual specimens should be wrapped in soft lint-free tissue or cellulose
wadding (not cotton wool, see A2.1.2.2) and packed firmly into rigid containers.
either as individuals or in groups, using crushed.paper or cotton wadding to
provide resilience between individuals. These containers should be wrapped in
the outer protective container with similar firmness. Polyether foam or expanded
polystyrene chips are good at this stage. Outer wrappings should be at least
shower-proof and tied with twine as well as adhesive strips at all margins of the
wrapping paper. Bubble-lined outer wrapping material is particularly good in
providing both moisture-resistance and impact protection. Particularly if being
sent overseas, ensure that all labelling of both sender and addressee, is clear, and
if possible use on at least one label and language of the recipient country.
The packing of large vertebrate specimens requires special techniques of
support and crating, and advice should be sought from a major museum. Large