National Instruments sbRIO-9651 Design Manual

Also see for sbRIO-9651: Quick start guide

Contents

National Instruments sbRIO-9651 Design Manual Manual pdf 62 page image

4-8 | ni.comChapter 4 Mechanical Considerations• External ambient—The maximum air temperature of the room or installation location thatsurrounds the system.• Internal/enclosure ambient—The maximum air temperature inside the enclosure. Thiscan be measured at various locations within the enclosure and is highly influenced by theproximity and dissipation of devices inside the enclosure.• Local ambient—The maximum air temperature as specified directly adjacent to theNI sbRIO device. This is measured on all sides of a device that has exposed circuitry.Because the sbRIO-9651 SOM has an integrated heat spreader on the primary side, onlythe secondary side needs to be measured.Because the system integrator may use any number of enclosure sizes, materials, thermalsolutions, and room conditions when designing an enclosure for a specific application, NI sbRIOdevices are specified in a manner that removes most of these external variables. Therefore, thesbRIO-9651 SOM thermal performance is not determined by measuring the external ambient orinternal/enclosure ambient temperatures, but by measuring the local ambient and specificcomponent temperatures. NI provides digitally reported temperatures to help you accuratelymeasure these critical temperatures.Validating the SystemNI recommends that you use a validation system for an extended period of time in a testenvironment with the same thermal, environmental, and functional utilization characteristics asthe target deployment environment. You are responsible for final validation of your application.Validating Temperature MeasurementsThe sbRIO-9651 SOM includes three onboard temperature-monitoring sensors to simplifyvalidation of a thermal solution, as shown in Figure 4-5. The sensors provide an indication ofthermal performance and are used to validate the system along with the local ambient operatingtemperature.