What is Uncertainties: Definition and 167 Discussions

In metrology, measurement uncertainty is the expression of the statistical dispersion of the values attributed to a measured quantity. All measurements are subject to uncertainty and a measurement result is complete only when it is accompanied by a statement of the associated uncertainty, such as the standard deviation. By international agreement, this uncertainty has a probabilistic basis and reflects incomplete knowledge of the quantity value. It is a non-negative parameter.The measurement uncertainty is often taken as the standard deviation of a state-of-knowledge probability distribution over the possible values that could be attributed to a measured quantity. Relative uncertainty is the measurement uncertainty relative to the magnitude of a particular single choice for the value for the measured quantity, when this choice is nonzero. This particular single choice is usually called the measured value, which may be optimal in some well-defined sense (e.g., a mean, median, or mode). Thus, the relative measurement uncertainty is the measurement uncertainty divided by the absolute value of the measured value, when the measured value is not zero.

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  1. E

    Uncertainties and LINEST in Excel....

    I don't think this qualifies as a homework question, as I can work around it; please move if necessary. I am currently doing a lab report on the Magnetic Susceptibility of different samples. In one part of this report I have to plot Force vs B^2, which is a linear fit. I have errors which have...
  2. Daaavde

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  3. Valour549

    Why is a leading figure of 1 so special in uncertainties?

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  4. P

    Uncertainty Calculation for 6mV Input on Linear Force Measuring Device

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  5. R

    What is the expected value of x^2 for a wave packet in momentum representation?

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  6. N

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  7. T

    Why is one significant figure the norm in uncertainties?

    Why is it that only one significant figure for any uncertainty is taught? It seems like a nice general rule, but isn't it an unnecessary constraint and ultimately a poor rule in many cases? For example ## 5 \pm 1 ## could mean an error of either 0.5 or 1.5, which is a very large range. Wouldn't...
  8. M

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  9. Aristotle

    Finding the Uncertainties in Frequency with Given Capacitor and Inductor Values

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  10. S

    What determines the precision of uncertainties?

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  11. Alex Haines

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  12. xyz_a

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    Homework Statement Remember: all answers (including uncertainties) must have three significant digits. For all problems: use the value of g given: g = 9.802 m/s2 0.0005 m/s2. Look at the diagram in the above image. Suppose the total mass of hook 2 is m2 = 951.0 g 2.3 g, and θ = 31.90o...
  13. S

    Error Propagation and Uncertainties in Parameters

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  14. G

    How do I account for measurement uncertainties in temperature data analysis?

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  15. E

    Rounding uncertainties and measurements

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  16. T

    Uncertainties of a group of results

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  17. A

    Help Understanding Uncertainties

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  18. L

    Determine the uncertainties

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  19. T

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  20. L

    Need some advice on uncertainties

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  21. J

    Calculating Uncertainties of Measured quantities (Physics)

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  22. J

    MHB Calculating Uncertainties of Measured quantities (Physics)

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  23. J

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  24. D

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  25. P

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  26. 0

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  27. J

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  28. nomadreid

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  29. N

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  30. P

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  31. S

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  32. Y

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  33. S

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  34. P

    Volume and density uncertainties lab

    Calculate the volume in (kg/m3) and density of a cube of unknown metal and its associated uncertainties. Then determine what kind of metal it is. Data is : side a= 19mm side b=19mm side c= 19mm. Mass of cube is 1.86g. Volume= a*b*c uncertainty ΔV= (Δa/a + Δb/b + Δc/c)V Density= m/v ΔD=...
  35. PhizKid

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  36. L

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  37. L

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  38. L

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  39. D

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  40. P

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  41. K

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  42. Loren Booda

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  43. J

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  44. Q

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  45. A

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  46. Z

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  47. L

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  48. J

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  49. C

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  50. N

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