How windy is it inside your chamber? Ours has large fans to circulate the air. Air moving across the surface of your EUT will pull the heat out lowing the external measurements. I really don't know how to get around this other than to turn off the fans to let the air go stagnant around the EUT. This would be worst case.
For fun, when you are doing thermals outside a chamber, once your external temps stabilize, turn on a fan and blow it at your EUT. The moving air will cause the external temps to drop. The EUT heats up the air around itself cause a higher reading on external temps. If you blow away this warm air the external reading will lower. The Other Brian -----Original Message----- From: Scott Xe [mailto:[email protected]] Sent: Wednesday, March 02, 2016 8:37 AM To: [email protected] Subject: [PSES] Ambient temperature We would like to verify the temperature rise at 40 degC ambient temperature. The sample under test was placed in a temperature chamber set at 40 degC. The internal temperatures were close but the external temperatures were marked different and even lower than the room temperature without using temperature chamber. Is there any standard method to create ambient temperature to have a repeatable testing conditions? Thanks and regards, Scott - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]> ________________________________ LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
