How to improve the measurement accuracy to that of relative accuracy?

[SAS]

We have got a NI6014E DAQ card, (16 bits). Though its relative accuracy is better (micro volts), its absolute accuracy is around 8mv only, for +/-10 volts range. Is there any way to make my measurements to have better accuracy (as that of the relative accuracy)? First of all, can I improve my accuracy more than the absolute accuracy mentioned in the specification?

[RIO-Todd]

The absolute accuracy is a specification of the device, which is defined for different voltage ranges. If your incoming signal range is small, you could change the input limits of the DAQ device and that would improve the accuracy. For instance, if your signal is between -.5 V and +.5 V you could configure the 6014 for an input range of +/-.5 V and this would improve the absolute accuracy to .471 mV. Decreasing the input range increases the resolution of the device, causing an increase in accuracy.

[SAS]

Hi,
Thank you for ur reply. But my signal range is +/- 10 volts only. So i can't reduce the signal range. How do i improve the measurement accuracy for the complete range.
Thanks
SAS