1. Systematic Errors Units and Measurement Systematic Errors

2. The type of error arises due to defect in the measuring device is known as systematic error. The systematic errors are tend to be in one direction, either positive or negative. Sources of systematic errors Instrumental Errors Instrumental Errors Units and Measurement Systematic Errors Personal errors Imperfection in experimental technique or procedure

3. Instrumental errors arise due to imperfect design or calibration of the measuring instrument. Units and Measurement Instrumental errors Instrumental error can be minimised by correcting measurement device and improving experimental techniques.

4. An error comes into play because of faulty procedure adopted by the observer is called personal error. Units and Measurement Personal errors Personal error comes into existence due to making an error in reading a scale. It is due to faulty procedure adopted by the person making measurement.

5. The error due to experimental arrangement, procedure followed and experimental techniques called Imperfection error. Units and Measurement Imperfection in experimental technique Clinical thermometer placed under the armpit of human body will always give a temperature lower than the actual value of the body temperature.

6. The error produced due to sudden change in experimental conditions is called "Random Error“. Units and Measurement Random errors For example: Sudden change in temperature, change in humidity, fluctuation in potential difference (voltage). It is an accidental error and is beyond the control of the person making measurement.