This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Experimental Uncertainties (Errors) Some references for the following discussion: [SQU85] G.L. Squires, Practical Physics, 3 rd edition, Cambridge University Press, Cambridge, 1985, p. 7-54. [TAY82] J.R. Taylor, An Introduction to Error Analysis, Oxford University Press, Oxford, 1982. [BRA83] S. Brandt, Statistical and Computational Methods in Data Analysis, North-Holland, Amsterdam, 1983. [BEV69] P.R. Bevington, Data Reduction and Error Analysis for the Physical Sciences, McGraw-Hill, 1969. Errors Assume you measure the resistance of a wire at two different temperatures and the two results are different. Does that mean that you have observed a temperature dependence of resistance? The answer is probably yes, provided that the uncertainty (or ‘error’) of the measurement is smaller than the difference between the two results. If you don’t know the errors of the two measurements, there is no way you can tell. Thus, a measurement of a physical quantity is meaningless if it is not accompanied by an estimate of its uncertainty. Systematic errors Systematic errors always have the same sign. For instance, the effect of temperature on steel measuring tape, or a faulty calibration of a voltmeter will lead to systematic errors. If one is aware of a systematic error one can usually take it into account by applying a correction to the data. There is no recipe to find and deal with systematic errors. Using care, ingenuity and imagination, the experimenter must make an attempt to identify potential sources of systematic errors. Additional experimenter must make an attempt to identify potential sources of systematic errors....
View Full Document
This note was uploaded on 01/20/2012 for the course P 309 taught by Professor Urheim during the Spring '11 term at Indiana.
- Spring '11
- The Land