Arbitrary number concentration (arb.num.c.)
Arbitrary number concentration 


Abbreviation 
Arb.num.c.  
Definition in words 
Note 1: The concept has two definitions. Note 2: The reference system is defined by the laboratory. 

Definition by equation 
Note: k_{procedure} is a constant defined by the measurement procedure (there is an approximately proportionality to a kindofquantity from the International System of Quantities) 

Result type 
Ordinal scale 


Ratio scale 



Unit 
International unit (IU) or procedure defined unit (p.d.u.) (nonSI units)  
Special rule(s) in the NPU syntax 
“Procedure” is stated in the specification to the kindofproperty in the NPU definition. “Procedure” indicates that the measurement procedure must be stated somewhere else than the NPU code and there may be difficulties in comparing values for the same NPU code. If the ratio scale is attributed to the NPU definition, the unit can be nonSI unit. If the unit is an International Unit (IU), an international certified reference material (e.g. WHO reference material) is specified in the specification to the kindofproperty. If there exist no international certified reference material, the laboratory can specify the unit at the placeholder, procedure defined unit. If ordinal scale is attributed, no unit is stated. 

Reference 

Laboratory field 
Examples 


Clinical Chemistry

Example 1 (ordinal) 

Generic abbreviated form  NPU29256 Marrow—Erythroid stem cell(EPO indep.); arb.num.c.(proc.) = ?  
Full form with a result  NPU29256 Marrow—Erythroid stem cell(EPO independent); arbitrary number concentration(procedure) = low  
Abbreviated form with a result  NPU29256 Marrow—Erythroid stem cell(EPO indep.); arb.num.c.(proc.) = low  
Written expression  The arbitrary number concentration of EPO independent Erythroid stem cell in Mr Smith’s Marrow is [low], compared with the arbitrary number concentration of EPO independent Erythroid stem cell in a reference system. The measurement is performed according to a procedure defined by the laboratory.  
Notes 


Clinical Microbiology 
Example 2 (ratio)  
Generic abbreviated form  NPU28905 P—Hepatitis B virus(DNA); arb.num.c.(WHO 97/750; proc.) = ? × 10³ IU/L  
Full form with a result  NPU28905 Plasma—Hepatitis B virus(DNA); arbitrary number concentration(WHO 97/750; procedure) = 150 × 10³ IU/L  
Abbreviated form with a result  NPU28905 P—Hepatitis B virus(DNA); arb.num.c.(WHO 97/750; proc.) = 150 × 10³ IU/L  
Written expression  The arbitrary number concentration of Hepatitis B virus(DNA) in Mr Smith’s plasma is [1.5] × 10³ IU/L. The measurement is performed according to a procedure defined by the given laboratory. The measurement unit is defined by the Certified Reference Material, WHO 97/750.  
Equation  
Example 3 (ratio)  
Generic abbreviated form  NPU58268 P—Human immunodeficiency virus 1(RNA); arb.num.c.(proc.) = ? (p.d.u.)  
Full form with a result  NPU58268 Plasma—Human immunodeficiency virus 1(RNA); arbitrary number concentration(procedure) = 176 arbitrary unit/L  
Abbreviated form with a result  NPU58268 P—Human immunodeficiency virus 1(RNA); arb.num.c.(proc.) = 176 arbitrary unit/L  
Written expression  The arbitrary number concentration of Human immunodeficiency virus 1(RNA) in Mr Smith’s plasma is [176] arbitrary unit/L. The measurement is performed according to a procedure defined by the given laboratory.  
Equation  
Notes  “Arbitrary unit” was chosen by a local laboratory as a proprietary measurement unit.and not an accepted international unit.  
Reproduction and Fertility 
Example 4 (ratio)


Generic abbreviated form  NPU18199 Sem—Spermatozoa; arb.num.c.(proc.) = ? (p.d.u.)  
Full form with a result  NPU18199 Semen—Spermatozoa; arbitrary number concentration(procedure) = 100 arbitrary unit/L  
Abbreviated form with a result  NPU18199 Sem—Spermatozoa; arb.num.c.(proc.) = 100 arbitrary unit/L  
Written expression  The arbitrary number concentration of Spermatozoa in Mr Smith’s semen is [100] arbitrary unit/L. The measurement is performed according to a procedure defined by the given laboratory.  
Equation  
Notes  “Arbitrary unit” was chosen by a local laboratory as a proprietary measurement unit.and not an accepted international unit.  
Example 5 (ratio)  
Generic abbreviated form  NPU54283 Sem—Spermatozoa(progressively motile); arb.num.c.(Direct swimup; proc.) = ? (p.d.u.)  
Full form with a result  NPU54283 Semen—Spermatozoa(progressively motile); arb.num.c.(Direct swimup; procedure) = 88 arbitrary unit/L  
Abbreviated form with a result  NPU54283 Sem—Spermatozoa(progressively motile); arb.num.c.(Direct swimup; proc.) = 88 arbitrary unit/L  
Written expression  The arbitrary number concentration of Spermatozoa in Mr Smith’s semen is [88] arbitrary unit/L. The measurement is performed according to a procedure defined by the given laboratory.  
Equation  
Notes  “Arbitrary unit” was chosen by a local laboratory as a proprietary measurement unit.and not an accepted international unit.  
Reference 
NPU database, https://www.ifcc.org/ifccscientificdivision/sdcommittees/cnpu/npusearch/ and http://www.labterm.dk/default.aspx 


Kindofproperty

Nominal kindofproperty

Kindofquantity

Ordinal kindofquantity

Arbitrary number concentration


Unitary kindofquantity

Rational kindofquantity

Arbitrary number concentration





Reference 

Date  Term  Note 

19960101  Arbitrary number concentration  Term established 
NPU term identifier 
QU50104 