Uncertainty in Measurement Significant Figures

Measurements of Length, Volume, and Mass Uncertainty in Measurement Significant Figures Problem Solving and Dimensional Analysis Temperature Conversions ... 

I Apply rules for significant figures to express uncertainty in measured and calculated values. 

OBJECTIVES To understand how uncertainty in a measurement arises. To learn to indicate a measurement s uncertainty by using significant figures. 

UNCERTAINTY IN MEASUREMENT We observe that the uncertainty inherent in all measured quantities Is expressed by the number of significant figures used to report the quantity. Significant figures are also used to express the uncertainty associated with calculations involving measured quantities. 

Measured value Precision of measurement Random uncertainty In the measurement Significant figures of measured value... 

Both uncertainty in measurement and significant figures are illustrated in Figure 3.7, which has two captions. The first caption focuses on uncertainty, and the second shows how to apply significant figures to the same measurements. Study these captions carefully now, before proceeding to the next paragraph. 

Uncertainty in measurement, uncertain (doubtful) digit, significant figures, exact numbers... 

Measured quantities are reported so that the number of digits reflects the uncertainty in the measurement. Significant figures are the non-place-holding digits in a reported number. 

Significant figures are also important because they guide us in reporting the result of an analysis. When using a measurement in a calculation, the result of that calculation can never be more certain than that measurement s uncertainty. Simply put, the result of an analysis can never be more certain than the least certain measurement included in the analysis. 

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