Apparent viscosity of unfilled asphalt is evaluated by a rotational viscometer  which measures the torque generated by a calibrated spindle rotating at a selected speed into a bitumen sample heated at precise temperature in the range between ambient temperature to 260° C. The measured relative resistance to rotation is converted, by a factor,  in viscosity units,  cP or mPa.s.

Technical Specifications:

Rotational speed range (r.p.m.): 0.3 – 100

Viscosity  range (cP): 100 – 13.000.000

Selectable speeds: 18

Precision:+/- 1% fs

Resolution:

Using low viscosity adapter: 0.01

For viscosity equal to or above 10.000 cP: 1

For lower than 10.000 viscosity cP: 0.1

Repeatability: 0.2%.