Zahn-Type Viscosity Cups Viscosity cup holds a standard volume of liquid, which flows through an orifice provided at the bottom. Lab-Fine controls the mechanical dimensions, which is very-very close to perfection on which volume is controlled Instrument: - These cups are made from stainless having long handle .The orifice is provided at the bottom having hemi-spherical shape. Very precision orifices are drilled as per the standard specification, which are numbered from no-1 to no-5.