At very low shear rates, structures deform so slowly that they can adapt continuously, maintaining a situation close to the equilibrium, and not building up any structural changes, despite the fact that the total amount of shear may be large. At these conditions and at a given temperature, the viscosity of a visco-elastic liquid has a limiting value. This value is called the Zero-Shear-Viscosity (ZSV) and is noted as n0. The aim of this paper is to describe a protocol that gives reliable results for conventional, Multigrade and polymer modified binders (limited elastomeric polymer content). The details of the protocol, such as the sample insertion, waiting time to reach an equilibrium, retardation and relaxation period are given. As the n0 value does not exist for highly modified binders having a yield stress (e.g gelled bitumen), an extension of such a protocol to a transient low-shear concept is discussed. For the covering abstract see ITRD E107185.