05-23-2006 11:43 AM
05-23-2006 12:04 PM
I am not sure if I calculated it correctly. What I understand is LSB = (Voltage range)/2^(bit).
I also tried to do some calculation following the decription of absolute accuracy in your data sheet. What I got is:
NI6132: AbsoluteAccuracy at 1.25V is ~ 700uV
NI6289: at 0.1V is 30uV.
I know that it is not fair to compare since they are at different voltage range. So my basic question becomes: is NI6132 good to measure signal ~ 100uV (or lower) accurately compared with NI6289?
Thanks.
sipher
05-24-2006
04:21 PM
- last edited on
04-16-2025
10:32 PM
by
Content Cleaner
Hello SiPHER,
The formulas for calculating absolute accuracy and the necessary constants are listed in the Specifications sheet for each board. For example, page 4 of the 6132/6133 Specifications document and pages 4 and 5 of the 628x Specifications contain tables with this information. The tables list a value for "Absolute Accuracy at Full Scale" which corresponds to the accuracy achieved when taking a measurement of the maximum voltage for a given range.
If you want to calculate the accuracy for a particular reading other than the full-scale voltage, you can use the formulas listed in the table for this purpose. I did a quick calculation for a voltage reading of 100 uV on each board, and I got the following results:
6132 - Absolute accuracy at 100 uV (1.25 V range): 358 uV
6289 - Absolute accuracy at 100 uV (0.1 V range: 13.6 uV
Based on these results, I would recommend the 6289 for your application. I hipe this information helps.
Best regards,