Viscosity is resistance to flow. Viscous samples require special consideration. There are several
separate issues, and these apply whether one desires to measure interfacial tension or contact
angles. Viscosity is measured in milli Pascal seconds (mPa s) which is numerically identical to
centi Poise (cp). Water has a nominal viscosity of 1cp or 1mPa s. Viscosity is a strong function
of temperature, dropping rapidly as temperature rises. A good place to get reference values for
viscosity is the CRC Handbook of Chemistry and Physics (www.crcpress.com).
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