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Error limits. The error limit is the extreme value that you might obtain due to the uncertainty of your instruments. Determine the uncertainty of your instruments. If you are using a scale that measures to the nearest .01 g the last digit is unsure. Your uncertainty would be +/- .01g.
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Error limits The error limit is the extreme value that you might obtain due to the uncertainty of your instruments.
Determine the uncertainty of your instruments. • If you are using a scale that measures to the nearest .01 g the last digit is unsure. • Your uncertainty would be +/- .01g. • If you are using a graduated cylinder that has gradations to the nearest mL, you estimate the .1 mL and your uncertainty is +/- .1mL
Determine the uncertainty extremes • If you are determining density you have 2 measurements: volume and mass. • You measured mass and got a average mass of 3.45g. • You measured volume and got a volume of 3.5 mL • Your value for the mass could also be 3.44 g or it could be 3.46 g because of the uncertainty of the instrument. • Your value for the volume could also be 3.4 mL or 3.6 mL because of the uncertainty of the instrument.
Determine the Error Limits • For the smallest error limit use the small value for the mass and the large value for the volume. • Example: 3.44g/ 3.6mL =.96 g/mL • For the largest error limit use the large value for the mass and the small value for the volume • Example: 3.46g/3.4 mL=1.0 g/mL