Rheological measurement system

A system 100 for rheological measurement of a viscoelastic sample 103, comprises; a sample holder 130, an indenter tip 111, a force sensor 104, an indentation mechanism 10, a position sensor 106 for measuring indentation depth of the tip, and a processing system 102; wherein the system is configured to receive a sample into the holder, use the indentation mechanism to urge the indenter tip toward the sample to indent the sample, acquire force data and indentation depth data during indentation of the sample, and using the processing system determine from the force and indentation data one or more rheological properties of the sample. Also disclosed is a temperature-controlled sample holder, in a measurement apparatus, and a method of determining Poisson’s ratio of a viscoelastic sample using force and indentation depth data.