Unit 1.1.3 - Limitation of Physical Measurement

• All measurements have an associated uncertainty
• observed value = error + true value
• Error can be random or systematic
• ± is the symbol used to show uncertainty
• Systematic error follows a set pattern
• Systematic error can be fixed through calibration of equipment
• Random error does not follow a set pattern
• Random error can be cancelled out through repetition
• Repeatable - when the same person uses the same equipment and generates the same results
• Reproducible - when someone else uses the same equipment and generates the same result
• Resolution - the measuring instruments maximum precision
• Accurate - how close the measurement is to it's true value
• Precise - how close the measurements are to each other