Is there a significant difference between using a sling psychrometer and a stable psychrometer. I have never really head the term "stable" psychrometer, does this simply mean a digital version? When calibrating a hygrothermo graph, should the wet/dry bulb reading be taken at a certain time of day? Can anyone suggest an affordable source of stable psychrometers? Thanks you can respond off list at: [log in to unmask] Rosemary Healy Presidio Trust _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com ========================================================= 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).