Number of entities (num.)

Synonym

Absolute frequency, number of particles, number of molecules

Abbreviation

Num.

Definition in words

Number of entities (component B) in system 1

Note 1: Number of entities is not a SI base kind-of-quantity. In clinical laboratory, it is considered as a base kind-of-quantity.

Note 2: Entities are things with distinct and independent existence

Note 3: Entities can be distributed into a category due to their common distinct characteristics

Definition by equation

Systematic terms

Number of component B in system 1
Ratio scale
  • Value sets are positive numerical values
  • Algebraic operations are allowed (a=nb; a≠nb)
Numerical values from 0-∞

Unit

1 (one), 103, 106, 109, 1012, 1015, 1018 etc.

Unit, one (1) is omitted in the NPU syntax

Non-recommended term

Count

Reference

Ferard G, Dybkaer R, Fuentes-Arderiu X. Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences : Recommendations 2016. 1 ed: Royal Society of Chemistry; 2016. 182 p.

Laboratory field

Examples

Clinical Chemistry

Example 1
Generic abbreviated
NPU03843 U—Erythrocytes; num.(proc.) = ? × 106
Full result NPU03843 Urine—Erythrocytes; number of entities(procedure) = 0.5 × 106
Abbreviated result NPU03843 U—Erythrocytes; num.(proc.) = 0.5 × 106
Written expression The number of Erythrocytes in Mrs. Smith’s urine is 0.5 × 106. The measurement is performed according to a procedure defined by the laboratory.
Equation

Reproduction and Fertility

Example 2
Generic abbreviated
NPU03454 Sem—Spermatozoa; num.(proc.) = ? × 106
Full result NPU03454 Semen—Spermatozoa; number of entities(procedure) = 150 × 106
Abbreviated result NPU03454 Sem—Spermatozoa; num.(proc.) = 150 × 106
Written expression The number of Spermatozoa in Mr. Smith’s Semen is 150 × 106. The measurement is performed according to a procedure defined by the laboratory.
Equation
Example 3
Generic abbreviated
NPU57215 Sem—Spermatozoa; num.(proc.) = ? × 109
Full result NPU57215 Semen—Spermatozoa; number of entities(procedure) = 0.12 × 109
Abbreviated result NPU57215 Sem—Spermatozoa; num.(proc.) = 0.12 × 109
Written expression The number of Spermatozoa in Mr. Smith’s Semen is 0.12 × 109. The measurement is performed according to a procedure defined by the laboratory.
Equation

Reference

NPU database, https://www.ifcc.org/ifcc-scientific-division/sd-committees/c-npu/npusearch/ and http://www.labterm.dk/default.aspx
  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Rational unitary kind-of-quantity

          • Number of entities

Reference

  • Dybkaer R. Concept system on ‘quantity’: formation and terminology. Accredit Qual Assur. 2013;18(3):253-60.
  • Dybkaer R. ISO terminological analysis of the VIM3 concepts ‘quantity’ and ‘kind-of-quantity’. Metrologia. 2010;47(3):127-34.
Date Term Note
2019-06-06 Number of entities Term established