Measurements, errors and uncertainties quiz

What is a measurand?

• Process of gathering information from physical world and comparing this information with agreed standards.

• Is the physical parameter under investigation.

• Value of the measured quantity.

Answer explanation

The physical quantity under measurement is termed as the measurand

What is the purpose of calibration in measurement?

• To reduce the cost of measurement processes.

• To increase the speed of data collection.

• To ensure the accuracy of measurement instruments.

Which of the following best describes a measurement uncertainty?

• The doubt that exists about the result of a measurement.

• The total error in a measurement process.

• The difference between the measured value and the true value.

Choose the answer with the correct definitions

• Repeatability: is the closeness of readings of sets of measurements made in the short term.

  Reproducibility: is the closeness of measurements when repeated over a longer time.

  Resolution: The smallest change in input reading that can be traced accurately.

• Repeatability: is the closeness of measurements when repeated over a longer time.

  Reproducibility: is the closeness of readings of sets of measurements made in the short term.

  Resolution: The smallest change in input reading that can be traced accurately.

• Repeatability: is the closeness of measurements when repeated over a longer time.

  Reproducibility: is the closeness of readings of sets of measurements made in the short term.

  Resolution: is a measure of change in readings for a given change in measured quantity.

• Repeatability: is the closeness of readings of sets of measurements made in the short term.

  Reproducibility: is the closeness of measurements when repeated over a longer time.

  Resolution: is a measure of change in readings for a given change in measured quantity.

Answer explanation

Repeatability: is the closeness of readings of sets of measurements made in the short term.

Reproducibility: is the closeness of measurements when repeated over a longer time.

Sensitivity: is a measure of change in readings for a given change in measured quantity.

Resolution: The smallest change in input reading that can be traced accurately

Choose the most appropriate answers (3 out of 5)

• Absolute error which is the difference between the “real value” of the measurand and the sensor reading

• Full scale (FS) error is the average absolute error divided by the range of the sensor or the full scale (i.e. the maximum value) of the sensor.

• Relative error which is the difference between the “real value” of the measurand and the sensor reading

• Relative error represents how the absolute error relates to the “real value” that was measured (with that error).

• Full scale (FS) error is the absolute error divided by the range of the sensor or the full scale (i.e. the maximum value) of the sensor.

Answer explanation

Absolute error which is the difference between the “real value” of the measurand and the sensor reading.

Relative error represents how the absolute error relates to the “real value” that was measured (with that error)

Full scale (FS) error is the absolute error divided by the range of the sensor or the full scale (i.e. the maximum value) of the sensor.

What statements are true about random errors?

• They occur irregularly.

• Bias by expecting a particular result

• Naturally occurring errors that are to be expected with any experiment

• Implementation of poor techniques in the measurement process

• 1010 m ± 21 m
• 1010 m ± 11 m

• 1020 m ± 21 m

• 1020 m ± 11 m

• 1010 ± 53 m

• 1010 ± 62m

• 1010 ± 71 m

• 1010 ± 291 m