Mitteilungen des Österreichischen Staatsarchivs 39. (1986)
Archive Buildings and the Conservation of Archival Material. An Expert Meeting, held in Vienna, Austria October 30 - November 1, 1985 - THOMAS, David: Architectural Design and Technical Equipment for the Physical Protection and Conservation of Documents
Architectural Design and Technical Equipment 243 sions which may, in turn, cause damage to the signal and to the oxide coating on the tape48). All these materials are also very susceptible to damage from air pollution. Sound recording discs and computer and sound tapes are easily damaged by particulates. Dust can contribute to loss of signal if it becomes trapped between layers of tape and can damage the backing and the magnetic coating49). Small particles in the grooves of discs can create distortion in playback and can lead to scratching. Photographic records can easily be harmed by air pollution. Particulates can make them dirty and cause scratching. Gaseous pollutants cause staining and fading of the image and may lead to the creation of microscopic blemishes - yellow or red spots - on microfilms50). Standards have been published for the preservation of records on these media. For sound recordings, the suggested ranges are 40—55% RH and 10—21° C for discs and 40-60% RH, 4-16° C for tapes51). The conditions should be constant within these ranges and the air should be purified of pollutants. For computer tapes, it is recommended that they be stored at a constant temperature and RH within the range 5—32° C and 20—80%; the air should be dust free and the storage area should be shielded from electro-magnetic interference52). Photographs demand rather different conditions. Black and white film should be stored at an RH of 30% and a temperature below 20° C. Prints should be stored at a constant temperature and RH within the range 15-25° C and 30-50% RH. Colour material should be stored at a temperature of 2° C or below and an RH of 30%. As a compromise, all photographic records, except for colour films and prints, can be stored at a constant temperature below 20° C and an RH in the range 30-50%53). These standards have implications for the design and construction of archive buildings. In the future, all archives will acquire large quantities of these materials. To preserve them properly they will have to acquire specially equipped storage areas which will provide filtration against particulate and gaseous pollutants. The storage area will need to be fitted with suitable metal shelving and cabinets and to have air-conditioning equipment which will maintain a constant temperature and RH. For reasons of economy, this will have to be close to the maxima of the ranges given above. A temperature of 20° C and an RH of 30-45% could be maintained far more economically than colder and drier conditions54). The use of underground storage (provided that 48) J. McWilliams The Preservation and Restoration of Sound Recordings (Nashville 1979) 24-25, 45. 49) Ibid. 47-48. 50) Klaus B. Hendriks The Preservation of Photographic Records in Archivaria 5 (1977/78) 98. 51) BS section 12.10.1; 12.11.1. 5J) Michael Roper The Changing Face of the File: Machine-Readable Records and the Archivist in Archives 14 (1980) 148-149. 53) ISO 6051 section 6.1-2; ISO 5466 section 7.1.2. 54) Kodak Preservation of Photographs 28. 16*
