which node referred for FaultModel:TemperatureSensorOffset:ReturnAir

I try to use EMS module to implement the return-air-temperature-sensor-offset for OA-Mixer. (FaultModel currently has a bug). But I face a problem: which node is the reference point for the sensor offset? Thanks.

As the name implies, it's the return air node.

An AirLoopHVAC:OutdoorAirSystem has four nodes:

Return Air Node
Relief Air Node
(Outside) Inlet Air Node (it gets air from a virtual "OutdoorAir:Node" that represents environmental conditions)
Mixed Air Node

OA System Node

All the air in the return path of the AirLoopHVAC gets to the Return Air Node, at which points a fraction can go to the Relief Air Node (to the outside) and the rest goes to the mixed air node. The mixed air node gets air from the return air node and the outside inlet node.

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