| 1.66 | true quantity value | ||
| true value of a quantity | |||
| true value | |||
| Quantity value consistent with the definition of a quantity. | |||
| Note 1: | In the Error Approach to describing measurement, a true quantity value is considered unique and, in practice, unknowable. The Uncertainty Approach34 is to recognize that, owing to the inherently incomplete amount of detail in the definition of a quantity, there is not a single true quantity value but rather a set of true quantity values consistent with the definition. However, this set of values is, in principle and in practice, unknowable. Other approaches dispense altogether with the concept of true quantity value and rely on the concept of metrological compatibility of measurement results for assessing their validity. | ||
| Note 2: | In the special case of a fundamental physical constant,35 the quantity is considered to have a single true quantity value. | ||
| Note 3: | When the definitional measurement uncertainty associated with the measurand is considered to be negligible compared to the other components of the measurement uncertainty, the measurand may be considered to have an “essentially unique” true quantity value. This is the approach taken by the GUM34 and associated documents, where the modifier “true” is considered to be redundant. | ||
| Source: [VIM 2.11]. | |||
| 1.66 | true quantity value | ||
| true value of a quantity | |||
| true value | |||
| Quantity value consistent with the definition of a quantity. | |||
| Note 1: | In the Error Approach to describing measurement, a true quantity value is considered unique and, in practice, unknowable. The Uncertainty Approach34 is to recognize that, owing to the inherently incomplete amount of detail in the definition of a quantity, there is not a single true quantity value but rather a set of true quantity values consistent with the definition. However, this set of values is, in principle and in practice, unknowable. Other approaches dispense altogether with the concept of true quantity value and rely on the concept of metrological compatibility of measurement results for assessing their validity. | ||
| Note 2: | In the special case of a fundamental physical constant,35 the quantity is considered to have a single true quantity value. | ||
| Note 3: | When the definitional measurement uncertainty associated with the measurand is considered to be negligible compared to the other components of the measurement uncertainty, the measurand may be considered to have an “essentially unique” true quantity value. This is the approach taken by the GUM34 and associated documents, where the modifier “true” is considered to be redundant. | ||
| Source: [VIM 2.11]. | |||