Hi Joe, Incoming air is 23C, 40%RH: At 90C, the relative humidity is 1.6% At 125C, it is 0.48%. Calculations are based on Vapor Pressure, dew point, Moisture Content, and temperature. http://www.usatoday.com/weather/whumcalc.htm The actual formulas used to be there, but I can't seem to find them now. -----Original Message----- From: Macko, Joe @ IEC [mailto:[log in to unmask]] Sent: Monday, March 29, 2004 11:33 AM To: [log in to unmask] Subject: [TN] oven drying of MSDs Technets, Commonly, Moisture Sensitive Devices (MSD) are baked out at either 125 C or 90 C in a convection air oven to remove moisture. J-STD-033A requires the humidity to be < or equal to 5% at 90 C. Would someone point me to an explanation of how to adjust the humidity content of the air at 125 C or 90 C when say the incoming air is at a humidity level of 40% and 23 C. If I remember correctly, warmer air can hold more moisture. Is a dehumidifier required in the air inlet to reduce ambient humidity levels to 5%? Look forward to your inputs. thanks joe --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------