Arbitrary shear stress (arb.shear stress)
Abbreviation 
Arb.shear stress  

Definition in words 
Arbitrary shear stress of component B in system 1 Note: Shear stress is “Force acting tangentially to a surface divided by the area of the surface” IUPAC Gold Book 

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). 

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 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. 

Reference 
Ferard G, Dybkaer R, FuentesArderiu X. Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences : Recommendations 2016. 1 ed: Royal Society of Chemistry; 2016. 182 p. doi:10.1039/9781782622451. 
Laboratory field 
Examples 


Thrombosis and Haemostasis 
Generic abbreviated form 
NPU54277 B—Coagulum shear strength(heparin indep.); arb.shear stress(surf. and tissue f.induc.coag.; proc.) = ? (p.d.u.) 
NPU54277 Blood—Coagulum shear strength(heparin independent); arbitrary shear stress(surface and tissue factor induced coagulation; procedure) = 25 arbitrary unit  
Abbreviated form with a result  NPU54277 B—Coagulum shear strength(heparin indep.); arb.shear stress(surf. and tissue f.induc.coag.; proc.) = 25 arbitrary unit  
Written expression  The arbitrary shear stress of heparin independent Coagulum shear strength is [25] arbitrary units. The measurement is performed according to a surface and tissue factor induced coagulation procedure defined by the laboratory.  
Equation



Notes

“Arbitrary unit” was chosen by a local laboratory as a proprietary measurement unit.and notan 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

Unitary kindofquantity

Rational unitary kindofquantity

Arbitrary shear stress





Reference 

Date  Term  Note 

20130515  Arbitrary shear stress  Term established 
NPU term identifier 
QU101066 