way, properly designed NI sbRIO devices may still require an external ambient temperature of
70 °C or less and may still require specific mounting requirements to ensure that the local
ambient and thermally-relevant component maximum operating temperatures are within
specification.
Understanding Thermal Specifications
A deployed system has several temperature measurement locations that indicate the thermal
performance of the system and the devices the system contains. For example, in a natural
convection system, the temperature of a critical component will be higher than the temperature
of the air in the immediate vicinity of the component. This local air temperature will also be
higher inside an enclosure than in the room ambient that surrounds the enclosure.
The following figure identifies these types of ambient temperatures.
Figure 10.
Ambient Temperatures
1
2
3
6
5
4
7
1. External ambient temperature
2. Internal/enclosure ambient temperature
3. Local ambient temperature
4. Enclosure
5. RMC board
6. NI sbRIO-9607
7. Thermal Kit for NI sbRIO-9607/9627/9637
(153901-02)
•
External ambient—The maximum air temperature of the room or installation location that
surrounds the system.
•
Internal/enclosure ambient—The maximum air temperature inside the enclosure. This can
be measured at various locations within the enclosure and is highly influenced by the
proximity and dissipation of devices inside the enclosure.
•
Local ambient—The maximum air temperature as specified directly adjacent to the
NI sbRIO device. This is measured on all sides of a device that has exposed circuitry.
NI sbRIO-9607 User Manual
|
© National Instruments
|
11
