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Reply To: | TechNet E-Mail Forum. |
Date: | Mon, 29 Mar 2004 12:09:01 -0800 |
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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
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