An Engineer is performing an overall uncertainty analysis of a system I am working on. A temperature channel consists of an RTD element, RTD transmitter, current loop resistor, and NI-9205 A/D in the cRIO chassis. Now, we know the uncertainty of the RTD, transmitter, resistor, and the NI-9205 because they are published in their respective documentation. To complete the uncertainty calculation the analyst now wants to know the accuracy of the calculation performed in the cRIO-9073. I have attempted to explain that the cRIO uses IEEE double precision libraries, which are dependent on the library implementation, and further are application dependent, but in the worst case is far more accurate than the application requires. I have pointed him to the IEEE standard. But he wants an authoritative reference to a National Instruments document that specifies the accuracy of math operations on the cRIO 9073.
Help, I am out of words. Does NI have any document(s) that makes any claim to math accuracy on the cRIO-9073?
