Alternatively, assuming the typical wire rack shelving in the chamber and a relatively small EUT, free air flow can be limited by placing three wire rack shelves onto adjacent levels that are out of the main air circulation pattern in the chamber and placing pieces of cardboard or corrugated fiberboard onto the two outer shelves, with the EUT on the center of the middle shelf. Place a thermocouple 25mm to 50 mm above the EUT to provide an ambient temperature measurement.
Never rely on the environmental chamber's controls or internal thermocouples for internal ambient air temperature measurement. They will rarely give the temperature at the location the EUT is placed. If the EUT is large the environmental chamber needs to be much larger than the EUT, as indicated by others. Peter Tarver - ---------------------------------------------------------------- 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 <emc-p...@ieee.org> 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 <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>