HL7 v2.5.1 Vocabulary
0.1.0 - ci-build

HL7 v2.5.1 Vocabulary, published by HL7/FO. This guide is not an authorized publication; it is the continuous build for version 0.1.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/frankoemig/hl7.v2.terminology.v251/ and changes regularly. See the Directory of published versions

CodeSystem: Kind of Quantity (2.5.1 - 1.0.0) (Experimental)

Official URL: http://terminology.hl7.org/v2plusvocab/CodeSystem/kindOfQuantity Version: 1.0.0
Active as of 2026-01-27 Computable Name: KindOfQuantity
Other Identifiers: OID:2.16.840.1.113883.18.149

Copyright/Legal: HL7 Inc., 2026

HL7 published code system of concepts that describe categories of an underlying kind of property represented by an observation. These are intended to distinguish concentrations from total amounts, molar concentrations from mass concentrations, partial pressures from colors, and so forth. These are discussed more fully in the LOINC Users’ Manual. These defined categories are derived from the approach described in 1995 edition of the IUPAC Silver Book. These distinctions are used in IUPAC and LOINC standard codes. Needs review by OO and HTA to determined if this is a value set built on LOINC part codes or some other external vocabulary.

This Code system is referenced in the content logical definition of the following value sets:

Properties

This code system defines the following properties for its concepts

NameCodeURITypeDescription
versionIntroduced versionIntroduced http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#versionIntroduced string version when was this code introduced
versionDeprecated versionDeprecated http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#versionDeprecated string version when was this code deprecated
status status http://hl7.org/fhir/concept-properties#status code A code that indicates the status of the concept. Typical values are active, experimental, deprecated, and retired
comment comment http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#comment string A string that provides additional detail pertinent to the use or understanding of the concept
usage usage http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#usage string usage notes for this code
modified modified http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#modified dateTime date of last modification

Concepts

This case-sensitive code system http://terminology.hl7.org/v2plusvocab/CodeSystem/kindOfQuantity defines the following codes:

CodeDisplayDefinitionversionIntroducedusagemodified
ABS Absorbance Absorbance 2.3
ACNC Concentration, Arbitrary Substance Concentration, Arbitrary Substance 2.3
ACT Activity Activity 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
APER Appearance Appearance 2.3
ARB Arbitrary Arbitrary 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
AREA Area Area 2.3
ASPECT Aspect Aspect 2.3
CACT Catalytic Activity Catalytic Activity 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
CCNT Catalytic Content Catalytic Content 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
CCRTO Catalytic Concentration Ratio Catalytic Concentration Ratio 2.3
CFR Catalytic Fraction Catalytic Fraction 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
CLAS Class Class 2.3
CNC Catalytic Concentration Catalytic Concentration 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
CNST Constant Constant 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
COEF Coefficient Coefficient 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
COLOR Color Color 2.3
CONS Consistency Consistency 2.3
CRAT Catalytic Rate Catalytic Rate 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
CRTO Catalytic Ratio Catalytic Ratio 2.3
DEN Density Density 2.3
DEV Device Device 2.3
DIFF Difference Difference 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
ELAS Elasticity Elasticity 2.3
ELPOT Electrical Potential (Voltage) Electrical Potential (Voltage) 2.3
ELRAT Electrical current (amperage) Electrical current (amperage) 2.3
ELRES Electrical Resistance Electrical Resistance 2.3
ENGR Energy Energy 2.3
ENT Entitic Entitic 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
ENTCAT Entitic Catalytic Activity Entitic Catalytic Activity 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
ENTNUM Entitic Number Entitic Number 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
ENTSUB Entitic Substance of Amount Entitic Substance of Amount 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
ENTVOL Entitic Volume Entitic Volume 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
EQL Equilibrium Equilibrium 2.3
FORCE Mechanical force Mechanical force 2.3
FREQ Frequency Frequency 2.3
IMP Impression/ interpretation of study Impression/ interpretation of study 2.3
KINV Kinematic Viscosity Kinematic Viscosity 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
LEN Length Length 2.3
LINC Length Increment Length Increment 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
LIQ Liquefaction Liquefaction 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
MASS Mass Mass 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
MCNC Mass Concentration Mass Concentration 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
MCNT Mass Content Mass Content 2.3
MCRTO Mass Concentration Ratio Mass Concentration Ratio 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
MFR Mass Fraction Mass Fraction 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
MGFLUX Magnetic flux Magnetic flux 2.3
MINC Mass Increment Mass Increment 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
MORPH Morphology Morphology 2.3
MOTIL Motility Motility 2.3
MRAT Mass Rate Mass Rate 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
MRTO Mass Ratio Mass Ratio 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
NCNC Number Concentration Number Concentration 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
NCNT Number Content Number Content 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
NFR Number Fraction Number Fraction 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
NRTO Number Ratio Number Ratio 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
NUM Number Number 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
OD Optical density Optical density 2.3
OSMOL Osmolality Osmolality 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
PRES Pressure (Partial) Pressure (Partial) 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
PRID Presence/Identity/Existence Presence/Identity/Existence 2.3
PWR Power (wattage) Power (wattage) 2.3
RANGE Ranges Ranges 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
RATIO Ratios Ratios 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
RCRLTM Reciprocal Relative Time Reciprocal Relative Time 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
RDEN Relative Density Relative Density 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
REL Relative Relative 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
RLMCNC Relative Mass Concentration Relative Mass Concentration 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
RLSCNC Relative Substance Concentration Relative Substance Concentration 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
RLTM Relative Time Relative Time 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SATFR Saturation Fraction Saturation Fraction 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SCNC Substance Concentration Substance Concentration 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SCNCIN Substance Concentration Increment Substance Concentration Increment 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SCNT Substance Content Substance Content 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SCNTR Substance Content Rate Substance Content Rate 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SCRTO Substance Concentration Ratio Substance Concentration Ratio 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SFR Substance Fraction Substance Fraction 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SHAPE Shape Shape 2.3
SMELL Smell Smell 2.3
SRAT Substance Rate Substance Rate 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SRTO Substance Ratio Substance Ratio 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SUB Substance Amount Substance Amount 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
SUSC Susceptibility Susceptibility 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
TASTE Taste Taste 2.3
TEMP Temperature Temperature 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
TEMPDF Temperature Difference Temperature Difference 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
TEMPIN Temperature Increment Temperature Increment 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
THRMCNC Threshold Mass Concentration Threshold Mass Concentration 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
THRSCNC Threshold Substance Concentration Threshold Substance Concentration 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
TIME Time (e.g. seconds) Time (e.g. seconds) 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
TITR Dilution Factor (Titer) Dilution Factor (Titer) 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
TMDF Time Difference Time Difference 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
TMSTP Time Stamp-Date and Time Time Stamp-Date and Time 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
TRTO Time Ratio Time Ratio 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
TYPE Type Type 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
VCNT Volume Content Volume Content 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
VEL Velocity Velocity 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
VELRT Velocity Ratio Velocity Ratio 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
VFR Volume Fraction Volume Fraction 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
VISC Viscosity Viscosity 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
VOL Volume Volume 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
VRAT Volume Rate Volume Rate 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21
VRTO Volume Ratio Volume Ratio 2.3 Adopted from the IUPAC Silver Book 1995” to the code 2015-08-21