Quantify Accuracy of Load Cell

[kayro]

Can't convince myself I'm doing this right.

0 - 25lb load cell
10V excitation
Rated Output: 2mV/V

nonlinearity: .10%
nonrepeatability: .05%
hysteresis: .10%
zero balance: 1.0%

E* = sqrt(.002^2 + .001^2 + .002^2 + .02^2) = 0.02 mv/V accuracy
*those numbers represent error % * Rated Output in mV/V

if I have 25lb/20mV full output at 10V excitation,
then my accuracy in lb is (25lb/20mV)*.02 mV/V = +/- .25 lb accuracy.

Disregard my amp and DAQ for the time being, I am just trying to assess the sensor. Thank you for any feedback, I can never straighten this out in my head.

 

[IRstuff]

At least two of the errors aren't really random, so RSSing isn't necessarily valid.

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[btrueblood]

Specifically, the hysteresis and non-linearity are not random errors. Also not clear why you doubled the error values in the RSS sum.

 

[IRstuff]

0.1% * 2mV = 0.002 mV

Zero balance isn't necessarily random either, depending on how you're using it, and how repeatable that is.

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[xnuke]

OP, can you please post a link to the datasheet?

xnuke
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[btrueblood]

Ahh, I read that as percent error, thanks Irstuff. And yeah, zero balance...