Artesyn MVME55006E Single Board Computer Installation and Use (July 2014) - Manual (Page 125)

Thermal Validation
MVME55006E Single Board Computer Installation and Use (6806800A37J) 125
B.3.1 Preparation
We recommend 40 AWG (American wire gauge) thermocouples for all thermal measurements.
Larger gauge thermocouples can wick heat away from the components and disturb air flowing
past the board.
Allow the board to reach thermal equilibrium before taking measurements. Most circuit boards
will reach thermal equilibrium within 30 minutes. After the warm up period, monitor a small
number of components over time to assure that equilibrium has been reached.
B.3.2 Measuring Junction Temperature
Some components have an on-chip thermal measuring device such as a thermal diode. For
instructions on measuring temperatures using the on-board device, refer to the component
manufacturer’s documentation listed in
Related Documentation on page 129 .
B.3.3 Measuring Local Air Temperature
Measure local component ambient temperature by placing the thermocouple downstream of
the component. This method is conservative since it includes heating of the air by the
component. The following figure illustrates one method of mounting the thermocouple.
Figure B-3 Thermalcouple Placement
Thermocouple
junction
PWB
Tape thermocouple wire to
top of component
Air flow