Dynamic viscosity (dyn.visc.) - Dynamic NPU Manual
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# Dynamic viscosity (dyn.visc.)

### Synonym

Coefficient of internal friction

Dyn.visc.

### Definition in words

Shear stress in the x,z plane in a fluid divided by velocity gradient perpendicular to the plane of shear (Reference 1)

Note 1: Shear stress is the “force acting tangentially to a surface divided by the area of the surface” (F/A)

Note 2: Velocity gradient is change of velocity divided by elapsed time (ΔV/ΔT)

### Systematic terms

Dynamic viscosity of component B in system 1

### Result type

Rational scale
• Value sets are positive numerical values
• Algebraic operations are allowed (a=nb; a≠nb)
Numerical values from 0-∞

### Unit

µPa s, mPa s, Pa s, etc.

### Special rule(s) in the NPU syntax

The Celsius Temperature of the measurement procedure should be stated.

Viscosity

### Reference

1. IUPAC Goldbook homepage. http://goldbook.iupac.org
2. 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.

### Clinical Chemistry

Example 1

Generic abbreviated form NPU28466 B—Blood; dyn.visc.(37 °C) = ? mPa s
Full form with a result NPU28466 Blood—Blood; dynamic viscosity(37 °C) = 3 milliPascal second
Abbreviated form with a result NPU28466 B—Blood; dyn.visc.(37 °C) = 3 mPa s
Written expression The dynamic viscosity of Mrs. Smith’s blood is [3] mPa s. The measurement is performed at 37 °C.
Equation
Example 2
Generic abbreviated form NPU27754 P—Plasma; dyn.visc.(37 °C) = ? mPa s
Full form with a result NPU27754 Plasma—Plasma; dynamic viscosity(37 °C) = 1.28 milliPascal second
Abbreviated form with a result NPU27754 P—Plasma; dyn.visc.(37 °C) = 1.28 mPa s
Written expression The dynamic viscosity of Mr. Smith’s plasma is [1.28] mPa s. The measurement is performed at 37 °C.
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

• ## Kind-of-quantity

### 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
2009-11-26 Dynamic viscosity Term established

QU100352