Absolute precision PXI-6123

Please see page 4 of the specifications for the device. The signal that I'm trying to measure through a shunt 30A: 300mV, but in most cases, the maximum value is about 10 A/100mV. The readings that we receive are not clean and are quite loud, when the hope is that they are quite clean.

It seems that the smaller card voltage range is +/-1.25 V. According to the manual, the absolute uncertainty according to the table is 740 uV (or 0.74 mV). I watched it and it was quite high. I mean in 2A (20 mV) absolute uncertainty of 0.75mV is 3.75% and it is quite high. I realize that we use only about 4% of the voltage range and it is a problem, but I still think it could be better that it's - am I interpreting this right?

If I interpret it correctly, then is card on par with the industry standards?


Please clarify, I was more in the way of solving problems to try and get the best representation of your signal! Take a look at this article by NOR retailer the absolute accuracy. You can calculate this using the values in the table on page 4 of the manual you mentioned.

How to calculate absolute precision or the accuracy of the system?


There are three ways to calculate absolute precision in anticipation of your system design, although I'll add the specification on page 4 of the manual I believe is the number planned and tested by NOR. I apologize because I'm a little busy right now or I would run the numbers myself.

Absolute accuracy specification is a signal that properly uses the +-1.25V range. A 0.74mV absolute precision in the schema of a 2.5Vpp signal is less than two-tenths of a percent error (0.185%). There are modules (as you mentioned) for smaller ranges of entry, that's why you have seen a performance much better with the-range 0.5 to 0.5. You might consider to amplify the signal in the range of +-1.25 to get the best performance with the PXI-6123. Although the distortion seems to be important in your application, using only 4% of the available range is just a case do not use the material best suited to your application.

Kind regards

Train of Finch

Tags: NI Hardware

Similar Questions

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    Many sculptures absolute accuracy calculated the computation of absolute precision in the manuals of the user for the use of modules in series C the following entries:

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    (2) if the room was 10 ° C when the measurement has been taken, both internal and external TempChanges is 15 ° C (because your calibration conducted at 25 ° C).

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    Regarding tips, I do not have too. The best I can suggest is to use a lower range and a device that has a lower production, but I don't think that it would be viable for your application. The best try of course is calibrated as close as possible to the more uniform temperature.

    I found a VI that calculates the absolute accuracy of a device. Must be a lot of values, but it allows you to play with the values to see what you can afford. My calculations show you in your range, but be absolutely sure of these fluctuations.


    Attached a photo of the values that I used to get this error. I'm sure that the devices are calibrated at 23 ° C. Here's the manual where I found the numbers that I used.


    Sorry for the confusion earlier, I hope that this post clears up a lot of information and if it's not please let me know.


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    I'm getting some strange noise on my with a BNC-2110 connector PXI-6123.  I think that there is a problem with the card.  I have confirmed that the signal entering the card does not have this noise.

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    I shorted the entrance of best in the world and you still see the problem.

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    Does it work? How can I know what are the "some data acquisition hardware OR" in the passage of the attachment?


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    With respect, the specification of sensitivity, this requires a more detailed explanation, but it is essentially an industrial standard that takes into account more statistical analysis on a signal when awarded with noise. According to me, the mix is a compoenent of this measure.

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