Before taking advantage of the automated set-up a calibration procedure was conducted to reduce the systematic measurements errors. This consisted of: (i) a pressure sensor calibration carried out using a digital pressure indicator (Druck, DPI 600/IS) applying a static pressure with air, and (ii) a full set-up calibration with aqueous glycerol solutions at known concentrations. In the latter case viscosity of the same samples was also measured by a commercial rotational viscometer (Rheometric Scientific, ARES G2) in order to rule out the systematic error introduced by the automated set-up. Additional information is provided in the Electronic Supplementary Information (ESI).