Measurement Errors

1. Definition

  • Error: The uncertainty in a measurement
  • All measurements are approximate due to errors

2. Types of Errors

2.1 Systematic Errors

Occur consistently in one direction (positive or negative)

Sources:

  • Instrumental errors
    • Imperfections in design/calibration
    • Zero errors
  • Experimental technique errors
    • Changes in external conditions (temperature, humidity, wind)
  • Personal errors
    • Individual bias
    • Improper setup
    • Carelessness in observations

Mitigation:

  • Improve experimental techniques
  • Choose better instruments
  • Minimize personal bias
  • Estimate and adjust for known systematic errors

2.2 Random Errors

  • Unpredictable and uncontrollable
  • Occur irregularly

Causes:

  • Fluctuations in experimental conditions
  • Imperfections in measuring instruments
  • Human factors (e.g., reaction time, technique variability)

Characteristics:

  • Different readings for repeated observations
  • Can be both positive and negative

Mitigation:

  • Take repeated measurements
  • Use statistical analysis
  • Calculate mean of multiple measurements

3. Best Practices

  • Always take multiple measurements
  • Calculate the mean to reduce errors
  • Use statistical analysis for random errors
  • Identify and correct systematic errors where possible