Understanding Precision and Random Errors in Intermediate Physics Laboratory Experiments
This lecture explores the concepts of precision and random (statistical) errors in experimental physics. Students will learn how to quantify these errors, distinguish between precision and accuracy, and apply error propagation rules in measurements. Special emphasis is placed on using statistical tools like the standard deviation and improving measurement techniques. The session includes a detailed analysis of a ruler exercise to measure the width of a table, recording best values and estimating random errors. Theoretical references will also be provided for deeper understanding.
Understanding Precision and Random Errors in Intermediate Physics Laboratory Experiments
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Presentation Transcript
Intermediate Lab PHYS 3870 Lecture 3 Quantifying Errors
Intermediate Lab PHYS 3870 Precision and Random (Statistical) Errors References: Taylor Ch. 2, 3 Also refer to “Glossary of Important Terms in Error Analysis”
Intermediate Lab PHYS 3870 Precision and Random (Statistical) Errors
Precision and Random (Statistical) Error 123.45 1 2 3 …
Reading a Vernier Scale A vernier scale provides a way to gain added precision from an instrument scale
Intermediate Lab PHYS 3870 The Ruler Exercise
Using the ruler provided, measure the width of the conference table. • Record, on the board, your “best” value and an estimate of the random error (the precision of your measurement) • Name Ruler Type Measured Value . The Ruler Exercise
Intermediate Lab PHYS 3870 Accuracy and Systematic Errors
Precision is defined as a measure of the reproducibility of a measurement Such errors are called random (statistical) errors. If an experiment has small random error, it is said to have high precision. Accuracy is a measure of the validity of a measurement. If an experiment has small systematic error, it is said to have high accuracy. Random and Systematic Errors
Comparison with Other Data Comparison of precision or accuracy?
Direct Comparison with Standard Comparison of precision or accuracy?
Independent (Random) Uncertaities and Gaussian Distributions
