| 1.59 | quantity | ||
| Property of a phenomenon, body, or substance, where the property has a magnitude that can be expressed as a number and a reference. | |||
| Note 1: | The generic concept ‘quantity’ can be divided into several levels of specific concepts, as shown in Table 1.4. The left-hand side of the table shows specific concepts under ‘quantity’. These are generic concepts for the individual quantities in the right-hand column. | ||
| Note 2: | A reference can be a measurement unit, a measurement procedure, a reference material, or a combination of such. | ||
| Note 3: | Symbols for quantities are given in the ISO 8000031 series Quantities and units. The symbols for quantities are written in italics. A given symbol can indicate different quantities. | ||
| Note 4: | The NPU format (Nomenclature for Properties and Units)5 preferred by IUPAC-IFCC for designations of quantities in laboratory medicine, is “System—Component; kind of quantity”, where each of the three segments may have parenthetic specifications. | ||
| Example: | “Plasma(Blood)—Sodium ion; amount-of-substance concentration equal to 143 mmol/l in a given person at a given time”. | ||
| Note 5: | A quantity as defined here is a scalar. However, a vector or a tensor, the components of which are quantities, is also considered to be a quantity. | ||
| Note 6: | The concept ‘quantity’ may be generically divided into, e.g., ‘physical quantity’, ‘chemical quantity’, and ‘biological quantity’, or base quantity and derived quantity. | ||
| Source: [VIM 1.1] with amended Note 4. | |||
| 1.59 | quantity | ||
| Property of a phenomenon, body, or substance, where the property has a magnitude that can be expressed as a number and a reference. | |||
| Note 1: | The generic concept ‘quantity’ can be divided into several levels of specific concepts, as shown in Table 1.4. The left-hand side of the table shows specific concepts under ‘quantity’. These are generic concepts for the individual quantities in the right-hand column. | ||
| Note 2: | A reference can be a measurement unit, a measurement procedure, a reference material, or a combination of such. | ||
| Note 3: | Symbols for quantities are given in the ISO 8000031 series Quantities and units. The symbols for quantities are written in italics. A given symbol can indicate different quantities. | ||
| Note 4: | The NPU format (Nomenclature for Properties and Units)5 preferred by IUPAC-IFCC for designations of quantities in laboratory medicine, is “System—Component; kind of quantity”, where each of the three segments may have parenthetic specifications. | ||
| Example: | “Plasma(Blood)—Sodium ion; amount-of-substance concentration equal to 143 mmol/l in a given person at a given time”. | ||
| Note 5: | A quantity as defined here is a scalar. However, a vector or a tensor, the components of which are quantities, is also considered to be a quantity. | ||
| Note 6: | The concept ‘quantity’ may be generically divided into, e.g., ‘physical quantity’, ‘chemical quantity’, and ‘biological quantity’, or base quantity and derived quantity. | ||
| Source: [VIM 1.1] with amended Note 4. | |||