The AAM Standard Facility Report asks for range of temperature and relative
humidity over the course of a year, since seasonal external fluctuations may
influence the internal environment, so I would say keep at least a year's
worth -- or transfer the information to some other kind of log.

Janice Klein
Registrar, The Field Museum
[log in to unmask]

 At 02:12 PM 11/11/1998 -0500, you wrote:
>We request institutions that wish to borrow artifacts to provide graphs
>covering four specific months of the previous year. While I am NOT a
>conservator, I really wonder how necessary it is to keep graphs for a period
>of years, unless you are gathering evidence to support the case for a new
>HVAC system!
>
>We tend to use ours more as a month to month tool for ensuring that there is
>not excessive deterioration of the more delicate artifacts (such as works on
>paper), due to environmental conditions.
>
>Harry Needham
>Special Advisor - Programme Development
>Canadian War Museum
>330 Sussex Drive,
>Ottawa, Canada
>K1A 0M8
>Voice: (819) 776-8612  Fax (819) 776-8623
>Email: [log in to unmask]
>
>> ----------
>> From:         Heather A. Ferrell[SMTP:[log in to unmask]]
>> Reply To:     Museum discussion list
>> Sent:         Wednesday, November 11, 1998 1:46 PM
>> To:   [log in to unmask]
>> Subject:      hygrothermograph charts
>>
>> Does anyone have any suggestions for how long an institution should keep
>> (or
>> currently keep) their hygrothermograph charts?
>>
>> Thanks for any information!
>> Heather Ferrell
>> Plains Art Museum, ND
>>
>
>