Intercomparison between NIS and IMGC Viscosity scales in the range from 14000 mm2/s to 70000 mm2/s and extension of the national viscosity scale from 70000 mm2/s up to 10000 mm2/s

A wide- range viscosity standard system has generally been realized with capillary viscometers, which are calibrated by the stepping-up method on the basis of viscosity value of distilled water at 10°C. An extension of this scale is being realized up to 100 000 mm2/s. The aim of this work is to realize the NIS viscosity scale and make an intercomparison between NIS-Egypt and IMGC-Italy in the range from 14 000 mm2/s to nearly 70 000 mm2/s. National Institute for standards (NIS) viscosity scale using glass capillary viscometers was realized for the first time during 2001. The scale was realized from 1 mm2/s to nearly 70 000 mm2/s. The values were obtained for NIS viscometers on subsequent recalibration over a period of some years. From the results obtained on recalibration of the National Institute for Standards viscometers and the comparisons made with IMGC-Italy it can be concluded that the present scale is realized with an uncertainty of about 0.4% at low viscosities (2 mm2/s) rising to about 1% at higher viscosities (1000 000 mm2/s).