Using the PCI-6025E board, I would like to understand how to translate the 12 bit resolution of the analog inputs into voltage resolution. The manual has a table of "accuracy information" on page A-2, but I am somewhat unsure of what all this means. It includes input voltage ranges, and for each range, there is a "theoretical relative accuracy" and an "averaged relative accuracy," the latter always being less than the former. For example, in the -10 V to 10 V range, it lists:
- Theoretical relative accuracy: 4.883 mV
- Averaged relative accuracy: 1.284 mV
This seems very confusing, since I would normally assume that a theoretically calculated parameter would be less than a measured one, so clearly I don't understand what this table is telling me.
In addition to not knowing what this data means, I also have one further question: Can an arbitrary offset (within the parameters of what the board can handle) be added to these ranges? For instance, say I want the same level of precision found in the -0.5 V to 0.5 V range, but I want to measure between 1.5 V and 2.5 V. Does setting this range ruin the precision characteristics listed in the aforementioned table?
Now I have also looked at table 3-2, which just lists precisions for specific ranges corresponding to gain settings (which admittedly is much easier to understand). However, this table also shows only symmetric input ranges, so the above question remains.
