Good Morning: If you are looking at conducting long-term environmental monitoring of T/RH/light/UV and dewpoint, I recommend investigating full data logging systems such as the HOBOs, Hanwells and ACRs. The Elsec is better used as a spot check device. As a conservator, I use the Elsec 764 made by Littlemore Scientific when I am conducting spot checks of environmental conditions as part of a general conservation assessment. I also have found it useful in a variety of other situations. For instance, when I am working with a client on-site and there are questions about immediate conditions: I can check discharge T/RH at air supply vents that may be located close to collections materials to make the case for relocating the object(s); to test UV filters for efficacy; in training sessions to show staff that reducing light levels does not always reduce visibility; and to check calibration of other equipment. I often work with an engineer who is interested in looking at dewpoint in historic structures as we are beginning to analyse the comportment of the building with respect to climate management for collections; the Elsec can give us a snapshot of this as well (note: we then use other types of instruments for the full evaluation). I purchased my Elsec 764 for about $1300 about 5 years ago with the data logging function from Scientific Sales in New Jersey. I believe that Art Conservation Services in NYC also sells them. There are probably other vendors out there as well. I believe that they are good instruments for spot checking environmental conditions. However, they do require regular calibration - especially the RH sensor. I regularly check the temperature readings against a mercury thermometer and have purchased the Elsec calibration kit for the RH sensor. When I get the chance I compare my UV and light readings against other equipment, knowing full well that there is a margin of error with all of this equipment and if we are within the margin of error for both pieces we should be OK. (Another note: some may fault the lack of absolute precision, but for the type of evaluation that I do, mostly working with collections housed in historic or retrofitted structures, I believe that this is acceptable.) I will only use the Elsec to check the calibration of hygrothermographs and hygrometers when I have recently calibrated the Elsec. The Elsec calibration kit uses 2 soluble salts that will create known RH in the closed chamber. This will calibrate to 2 points (high and low RH). I have colleagues who recommend 3-point calibration for greater accuracy. I have rarely used the data logging function of the Elsec because I have found other types of equipment (HOBO Pro-8 loggers for T&RH, from Onset Computer, for instance) easier to use. But in a pinch it has come in handy when I haven't tossed in an extra logger before I go on-site. There are other good hand-held instruments out there. I am not sure, but I believe that the Elsec is the only one that can be used to spot check T/RH/UV and light. Please weigh in, other conservators out there, if you have additional information on other equipment. Hope this provides the information you need. Please feel free to contact me if you have any additional questions. Wendy Conservator Wendy Jessup and Associates, Inc. Care of Cultural Property 933 North Kenmore Street, Suite 323 Arlington, VA 22201 (703) 522-2801 Fax: (703) 522-2802 www.collectioncare.com -----Original Message----- From: Museum discussion list [mailto:[log in to unmask]] On Behalf Of John Martinson Sent: Thursday, May 18, 2006 4:38 PM Subject: Environmental monitor and data logger, Type 764 Do any of you use the Littlemore Scientific Engineering ELSCEC monitor & data logger? They are made in the UK but are there a distributors or counter-parts here in the States? Do you have a general idea what they run/price? Are they a good product for tracking UV, visible light, % relative humidity, dew point and temperature? Thanks in advance. John Boise, ID ========================================================= 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).