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Uncertainty Propagation

  1. Jan 18, 2016 #1
    Say I have a 0-10 lbf load cell that can measure the force it takes to lift an object. The load cell is accurate to 1% of the full scale. I take 5 measurements and get the following readings:

    5.2, 5.1, 4.9, 5.0, & 4.8, all in lbf.

    Now I am asked to give the mean with the associated uncertainty. The mean is going to be 5 lbf with a standard deviation of 0.16 lbf. Am I correct to say that the total uncertainty is going to be:

    u = √((10 lbf * 0.01)2 + (0.16)2) = 1.01 lbf ?

    In addition, I think I am missing a step because of the small sample size. Any help is appreciated in advance.
  2. jcsd
  3. Jan 18, 2016 #2


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    Science Advisor

    I am not sure what you mean by "total uncertainty". I would say that the associated uncertainty is the standard deviation 0.15 lbf.
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