Example Uncertainty Propagation

density of a game cube:



Part I:

single measurement of a single cube, accuracy of scale is Δm=0.2g, accuracy of length measurement is Δl=0.1mm

l=20mm, m=200g



Part II:

Now a statistical analysis of a set of three cubes' densities is conducted:



length

mass



length

mass

cube 1

21mm

201g

cube 2

22mm

204g

cube 3

18mm

194g



Average of the length:

 

Standard deviation of the length:

 

Average of the mass:

 

Standard deviation of the mass:



Resulting uncertainty of the cube's density:



Institut für Mechatronik im Maschinenbau (iMEK), Eißendorfer Straße 38, 21073 Hamburg