A follow-up note on low-end RH with the Hobo loggers. While the specs on the web site list a low end of 25%, the loggers actually record lower than that. The Hobo H8 loggers (old style) record down to the single digits, theoretically to 0, but I have not personally seen such a reading. I have seen them record down to 5% or 6%. The Hobo U10 (new style) stops recording at 15%. Below that, it simply flatlines at 15%. The new U-series has definite advantages over the H8, not the least of which is that Onset no longer supports or develops the H8, while the software for the U-series will be updated/improved periodically. But if you really need to know the exact RH below 15%, the H8 is the only option. In my opinion, for most museum applications (especially historic sites), the Hobos are the best alternative, and more expensive loggers are wasting your precious money. Marc American Conservation Consortium, Ltd. 4 Rockville Road Broad Brook, CT 06016 www.conservator.com 860-386-6058 *Collections Preservation Consultation *Conservation Assessments & Surveys *Low-Tech Environmental Control *Moisture Management Solutions *Collections in Historic Structures *Conservation Treatment of: Furniture Painted Wood Horse-Drawn Vehicles Architectural Interiors Marc A. Williams, President MS in Art Conservation, Winterthur Museum Program Former Chief Wooden Object Conservator, Smithsonian Institution Fellow, American Institute for Conservation (AIC) ----- Original Message ----- From: "Susan L. Maltby" <[log in to unmask]> To: <[log in to unmask]> Sent: Thursday, January 11, 2007 11:13 AM Subject: Re: [MUSEUM-L] HOBO Hygrothermographs I concur that Hobos are great loggers. A word of caution though. You should carefully read the specifications & sensitivity ranges for the loggers to be sure they suit your application. For example, some loggers do not record in the really low end of RH - if you get really low levels & want accurate readings then you should choose your logger accordingly. Also, for outdoor use - there are only a few - the HoboPro (white, about the size of a hockey puck) & the pendant loggers (read light intensity & temperature) are designed to go out of doors. Susan Maltby, Conservator Maltby & Associates Inc. Adjunct Faculty, Museum Studies Programme/FIS University of Toronto Quoting "Meredith L. Dunham" <[log in to unmask]>: > We use three different types of HOBO loggers (door, soil, temp/RH) and > they all work very well. They're easy to download, print immediate > graphs or data lists (from a computer loaded with the appropriate > software), and the data can be converted to an Excel format for other > purposes. We placed the loggers outside, inside, in cases, in fireplace > flues, in attics, and just about anywhere you could want them. And they > don't need batteries that often. If you go with the shuttle off-load > method, I have easily downloaded between 8 and 12 loggers with a month's > worth of data and transferred it our computer. And they really do give > you an easy-to-understand look at your environment. > > Meredith Dunham > Curatorial Assistant > > Virginia Beach Historic Houses > 3131 Virginia Beach Blvd. > Virginia Beach, VA 23452 > Phone: 757-431-4000 > Fax: 757-431-3733 > Email: [log in to unmask] > > ________________________________ > > From: Museum discussion list on behalf of Sue Frank > Sent: Wed 1/10/2007 2:14 PM > To: [log in to unmask] > Subject: [MUSEUM-L] HOBO Hygrothermographs > > > > Can someone bring me up-to-speed about HOBO hygrothermographs? We > don't use these at the Phillips Collection, but I know other museums use > them. Are these more accurate than the paper recording units? Is it > correct > that you don't have to calibrate them monthly? How often do you have to > calibrate them? Thanks. > > ========================================================= > > > > ========================================================= > Important Subscriber Information: > > The Museum-L FAQ file is located at > http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed > information about the listserv commands by sending a one line e-mail > message to [log in to unmask] . The body of the message should > read "help" (without the quotes). > > If you decide to leave Museum-L, please send a one line e-mail message > to [log in to unmask] . The body of the message should read > "Signoff Museum-L" (without the quotes). > ========================================================= Important Subscriber Information: The Museum-L FAQ file is located at http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed information about the listserv commands by sending a one line e-mail message to [log in to unmask] . The body of the message should read "help" (without the quotes). If you decide to leave Museum-L, please send a one line e-mail message to [log in to unmask] . The body of the message should read "Signoff Museum-L" (without the quotes). ========================================================= Important Subscriber Information: The Museum-L FAQ file is located at http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed information about the listserv commands by sending a one line e-mail message to [log in to unmask] . The body of the message should read "help" (without the quotes). If you decide to leave Museum-L, please send a one line e-mail message to [log in to unmask] . The body of the message should read "Signoff Museum-L" (without the quotes).