![Calculation of % error
*Absolute error = measured value - exact value
= ׀VA - VE ׀
*Relative error = [measured value - exact value] /
exact value
= ׀VA - VE / VE ׀
*Percentage error = [measured value - exact value] /
exact value x 100%
*Percentage error = ׀VA - VE / VE ×׀ 100%](https://image.slidesharecdn.com/typesoferrors-200818070821/85/Types-of-errors-3-320.jpg)
Types of errors
- 1. Errors in Measurement System
- 2. Definition *An error may be defined as the difference between the measured value and the actual/true value. *The actual/true value is the average value of an infinite number of measured values. *Measured value is the estimated value of true value that can be found by taking several measured values during an experiment.
- 3. Calculation of % error *Absolute error = measured value - exact value = ׀VA - VE ׀ *Relative error = [measured value - exact value] / exact value = ׀VA - VE / VE ׀ *Percentage error = [measured value - exact value] / exact value x 100% *Percentage error = ׀VA - VE / VE ×׀ 100%
- 4. Types of Errors in Measurement System
- 5. Gross Errors *Gross errors are caused by mistake in using instruments or meters, calculating measurement and recording data results. (human errors) *Such errors may end up in calculation of the final results, thus deviating results.
- 6. Systematic errors *Systematic errors occur due to fault in the measuring device. *Usually they are called as Zero Error – a positive or negative error. *These errors can be removed by correcting the measurement device.
- 7. Systematic errors are classified into *Observational Errors: These occur due to wrong observations or reading in the instruments. (most common parallax error) *Environmental Errors: These occur due to some external conditions of the instrument. (change in temperature, humidity etc.) *Instrumental Errors: These occur due to wrong construction of the measuring instruments.
- 8. Instrumental errors may occur due to: *Hysteresis or friction. *Loading effect and *Misuse of the instruments.
- 9. Random errors *Random errors are caused by the sudden change in experimental conditions. These errors are due to unknown causes. *They are generally accumulation of a large number of small effects and may be of real concern. *These errors can be analysed statistically. *Noise can cause random errors in measurements. Hence, it is important to know the types of errors and minimise them so that measured data is interpreted properly.
- 10. The End