Question of the week: Week 14 of 2011 -- What are absolute error, relative error, and reference error?

The difference between the measured value and the true value is the absolute error; the absolute error divided by the measured value and multiplied by 100 gives the relative error; the absolute error divided by the range and multiplied by 100 yields the fractional error.

This post was last edited by denghl on 2012-12-1 at 19:45. The absolute error is the difference between the measurement result and the true value; that is: Absolute error = Measurement value – True value. The relative error is the ratio of the absolute error to the value being measured, and it is often expressed as a percentage by taking the ratio of the absolute error to the instrument’s reading, that is: Relative error = Absolute error / Instrument reading × 100%. The reference error is the ratio of the absolute error to the range, also expressed as a percentage, that is: Reference error = Absolute error / Range × 100%

This post was last edited by denghl on 2012-12-1 19:45. Absolute error: In measurements, it is the difference between the measured value and the true value of the quantity being measured. Relative error: In measurement, it is the ratio of the absolute error to the true value of the quantity being measured. In practice, the measured value of the quantity being tested differs little from its true value, and the relative error is often expressed as the ratio of the absolute error to the measured value. Quoted error: the ratio of the absolute error to the full scale value of the instrument. The absolute error is equal to the difference between the measurement result and the true value of the quantity being measured. The relative error is equal to the ratio of the absolute error to the true value of the quantity being measured, expressed as a percentage. The reference error is equal to the ratio of the absolute error to the upper range limit of the instrument, expressed as a percentage.

This post was last edited by denghl on 2012-12-1 at 19:45. The absolute error is the difference between the measurement result and the true value; that is: Absolute error = Measurement value – True value. The relative error is the ratio of the absolute error to the value being measured, and it is often expressed as a percentage by taking the ratio of the absolute error to the instrument’s reading, that is: Relative error = Absolute error / Instrument reading × 100%. The reference error is the ratio of the absolute error to the range, also expressed as a percentage, that is: Reference error = Absolute error / Range × 100%

This post was last edited by denghl on 2012-12-1 at 19:45. The absolute error is equal to the difference between the measurement result and the true value of the quantity being measured. The relative error is equal to the ratio of the absolute error to the true value of the quantity being measured, expressed as a percentage. The reference error is equal to the ratio of the absolute error to the upper range limit of the instrument, expressed as a percentage.

This post was last edited by denghl on 2012-12-1 19:46. The absolute error is the difference between the measurement result and the true value; that is, absolute error = measured value – true value； The relative error is the ratio of the absolute error to the value being measured; it is often expressed as a percentage, using the ratio of the absolute error to the instrument’s reading, that is, relative error = absolute error/instrument reading × 100% ； The reference error is the ratio of the absolute error to the range, expressed as a percentage; that is, reference error = absolute error / range × 100%.

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This post was last edited by denghl on 2012-12-1 at 19:46. I learned it before, but I can’t remember it exactly. Probably, the difference between the measured value and the true value is the absolute error; the absolute error divided by the measured value multiplied by 100% gives the relative error; and the absolute error divided by the range multiplied by 100% is the percentage error.

Absolute error: Let the true value of a measured quantity N be N’, and let the error be ε = |N’ – N|. This value reflects the extent to which the measured value deviates from the true value, and it is called the absolute error. Relative error: Since the absolute error cannot be used to compare the reliability of different measurement results, people use the ratio of the absolute error of a measurement value to that value itself to evaluate it; this is known as relative error. It is denoted by and can be expressed as a percentage, also referred to as percent error. Reference error is a common method for expressing errors in instruments. It represents the error relative to the instrument’s full scale; the ratio of the absolute measurement error to the instrument’s full scale value is known as the instrument’s reference error, which is usually expressed as a percentage.

This post was last edited by denghl on 2012-12-1 19:46. Answer: The absolute error is equal to the difference between the measurement result and the true value of the quantity being measured. The relative error is equal to the ratio of the absolute error to the true value of the quantity being measured, expressed as a percentage. The reference error is equal to the ratio of the absolute error to the upper range limit of the instrument, expressed as a percentage