# Lecture1Errors in MeasurementsFall23handout

.pdf
8/25/2023 1 1-1 Uncertainties in Analytical Measurements 8/25/2023 2 1-2 ACCURACY & PRECISION Treatment of Data:
8/25/2023 3 1-3 Reliability of Data ๏ง Precision - reproducibility of results - represented by the standard deviation & variation ๏ง Accuracy - correctness of result - expressed as relative or absolute error (E a ) ๐ฌ ๐ เต ๐ฬ เต ๐ ๐ ๐ซ๐๐ฅ๐๐ญ๐ข๐ฏ๐ ๐๐ซ๐ซ๐จ๐ซ เต ๐ฬ เต ๐ ๐ ๐ ๐ เต ๐๐๐ % 8/25/2023 4 1-4 Measurement Precision The Tale of Two Balances: - Balance 1: ยฑ 0.1 g Measurements Precision 12.3 0.813 % 12.4 0.806 % - Balance 2: ยฑ 0.0001 g Measurement s Precision 12.3115 0.00081225 % 12.3667 0.00080862 %
8/25/2023 5 1-5 Precision & Accuracy โข Speed of light (3 ร 10 8 m/s) measurements: Measurements Precision Accuracy (2.5005 ยฑ 0.0002) ร 10 8 m/s 0.008 % low (2.50 ยฑ 0.08) ร 10 8 m/s 30 % high โข Why do you think it's important to keep the correct number of significant figures when reporting measurements? โข Why can't measurements be always precise & accurate? 8/25/2023 6 1-6 ERRORS & UNCERTAINTIES Treatment of Data: