Accuracy in measurement

• An accurate measurement is one that is close to the true value.
• We must avoid two types of errors:

  1. Zero error
  2. Parallax error
• Zero error occurs when an apparatus shows a none zero reading when the true reading is zero.
• Parallax error occurs when the observer wrongly places his eyes when taking a measurement.
• How to avoid parallax error:

  The observer must place his line of sight perpendicular to the scale at the point of measurement.