Discussion: Should we choose the true value or the measured value?
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Should one choose the true value or the measured value? A few days ago, a fill-in-the-blank question sparked controversy. The question read as follows: Relative error is the percentage of the ratio between (absolute error) and ( ). Currently, there are two opinions: one is that the true value of the quantity being measured should be filled in, while the other is that the measured value of that quantity should be used. It is difficult to reach a consensus between these views; please state your choice and explain your reasons. Thank you!
What’s there to discuss about the definition when it relates to the true value of what is being measured?
The true value being measured. Since the truth value cannot be determined, “conventional truth values” are used as a substitute in actual measurements. If the measured value of the quantity being measured is used, then different values for this quantity may arise in each measurement, making it difficult to determine the relative error. My humble opinion
It is impossible to obtain the truth value, because measuring is necessary in order to get it； So it should be the standard value of the true value, that is, the measured value from a high-precision gauge.
Agree with the view on the third floor. But for an exam, the true value of what is being measured should be filled in!
The true value of what is being measured is unknown; in actual measurements, the measured value is usually used in place of the true value for calculations. In such cases, the relative error becomes the nominal relative error, but calculations should be performed using the true value.
Instrument Technician Question Bank (2nd Edition), Field Instruments Volume. The relative error is defined as the ratio of the absolute error to the measured value; it is commonly expressed as relative error = (absolute error / instrument reading) * 100%
That is incorrect; the definition of relative error, regardless of the context, is the ratio of the absolute error to the true value of the quantity being measured.
The true value being measured. The definition is considered from Yan Jin’s perspective and holds up to practical testing.
I think the true value should be chosen, because there are errors in the measured values themselves