ISO 12058-1:2018

Plastics — Determination of viscosity using a falling-ball viscometer — Part 1: Inclined-tube method

This document specifies the general principles of a method, using an inclined-tube falling-ball viscometer, for determining the viscosity of polymers and resins in the liquid emulsified or dispersed state. It is intended for application to liquids over a viscosity measurement range of 0,6 mPa·s to 250 000 mPa·s (temperature range -20 °C to +120 °C) for which the shear stress and shear rate are proportional, i.e. the viscosity is independent of the shear rate. This ideal behaviour is commonly known as Newtonian behaviour. If a liquid differs significantly from this behaviour, different results can be obtained with the different balls of a falling-ball viscometer or from viscometers with different geometries, such as capillary and rotational viscometers.