All, The idea that "moving air is cooling air” is incorrect. This is only true if there is a temperature difference between the airstream and the hot object. If the the air stream and the object are at the same temperature, no cooling will occur. If the airstream is hotter than the object, then heating will occur.
Doug Nix > On 2-Mar-16, at 10:06, Scott Xe <[email protected]> wrote: > > Brian, > > I also suspect the forced air circulation may help the heat dissipation. > This variation will affect the result. When we conduct temperature rise at > room temperature, we will place the sample inside the test corner and block > the airflow directly from the top to the sample. It seems when we use > temperature chamber for other ambient temperature, the repeatability is quite > challenge. > > Regards, > > Scott > >> On 2 Mar, 2016, at 10:10 pm, Kunde, Brian <[email protected]> wrote: >> >> 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]> > > - > ---------------------------------------------------------------- > 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]> - ---------------------------------------------------------------- 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]>
