This International Standard specifies a procedure for the determination of the kinematic viscosity of mineral insulating oils, both transparent and opaque, at very low temperatures, after a cold soaking period of at least 20 h, by measuring the time for a volume of liquid to flow under gravity through a calibrated glass capillary viscometer.
It is applicable at all temperatures to both Newtonian and non-Newtonian liquids having viscosities of up to 20 000 mm × s. It is particularly suitable for the measurement of the kinematic viscosity of liquids for use in cold climates, at very low temperatures (-40 ℃) or at temperatures between the cloud and pour-point temperatures (typically -20 ℃) where some liquids may develop unexpectedly high viscosities under cold soak conditions.
BS EN 61868:1999 history
1999BS EN 61868:1999 Mineral insulating oils. Determination of kinematic viscosity at very low temperatures