ni 6008 accuracy

[lrojo]

Hi everyone!

I was wondering what the parameter accuracy of the NI-6008 means. It is 14.7 mv in RSE configuration. 

Does this number show the minimum value that the Ni-6008 can detect? i.e. the resolution?

Thanks

Lander

[crossrulz]

Accuracy is more of how close the measurement is from the true.  Resolution is the smallest change that can be detected.  While related, they are separate.

[lrojo]

Got it. Thanks!!

So the 14.7mV would be the absolute accuracy and the resolution would be 10-(-10)/2^11 =9.76 mV. I do not find this value anywhere.

Thanks again.

Lander

[johnsold]

Apparently they left the resolution for you to calculate, which you did.  Note also that the noise can be 5 Vrms.  It is possible that the accuracy figure was based on averages which eliminated the noise effects.  In a real world system you might see 2 or 3 LSB variations due to noise and accuracy limitations.

Lynn

[crossrulz]

You calculation should be (10- -10)/(2^12) = 4.88mV.  So the resolution at the full range is 4.88mV.  An accuracy of 14mV makes more sense with this.

[johnsold]

The specified resolution for the USB-6008/6009 is one bit less when using a single ended configuration. So 2^11 is the correct factor.

Lynn

[lrojo]

OK! Thank you all very much!