How to calculate uncertainty of signal acquisition with NI USB-6009 DAQ?

[nepomnyi]

Hello dear NI community.

I'm using NI USB-6009 DAQ board to acquire voltages from 3 pressure transducers and 1 turbine flow meter. I use analog inputs for that.

I - obviously - need to know uncertainty which I acquire my data with. When we calculate uncertainty, we account for each device in the chain of devices being used for data acquisition.

In my case, my DAQ is one of the devices in the chain and I need to know its accuracy to plug it into the formula for the total uncertainty.

I can't seem to be able to figure out the accuracy of my DAQ.

I read the specs (attached), but I don't understand it. Characteristics of the analog inputs are given on pages 1 and 2. I don't understand which one I can safely use for the DAQ's accuracy.

I read this as well. But the specs for my DAQ do not have gain error, offset error and flatness.

Searching the Internet hasn't been fruitful.

I'm wondering what the formula is and where I obtain the parameters for the formula in order to calculate the accuracy of NI USB-6009 DAQ AI signal acquisition.

Thank you in advance.

Ivan

[santo_13 · Accepted solution]

USB-6009 is part of the low-cost DAQ in the NI portfolio, instead of a detailed gain and offset errors, the specifications provide that absolute maximum error instead.

You can consider the "Maximum over Temperature" as the accuracy number that will be satisfied by the device across its working temperature range.

You need to get a high-end DAQ device for the more detailed specifications that you ask for, like USB-6363.