Pressure cell for rheological experiments under oscillatory shear and pressure

1. A measuring device for measuring an elasticity and a viscosity of a medium, the measuring device comprising:

a volume for receiving the medium to be measured, said volume being delimited by a first part,

a second part that protrudes into the volume;

wherein:

the first part in relation to the second part is sealed by way of a gas flow seal, and

the first part in relation to the second part is movable in a rotating movement and a predefined axis,

wherein the gas flow seal comprises:

the first part in a region of the gas flow seal has a first cylindrical sleeve portion and a second cylindrical sleeve portion,

the second part in a region of the gas flow seal has a first cylindrical portion and a second cylindrical portion,

the first cylindrical sleeve portion of the first part and the first cylindrical portion of the second part form a first cylindrical gap,

the second cylindrical sleeve portion of the first part and the second cylindrical portion of the second part form a second cylindrical gap, and

a pressurized gas supply is provided between the first cylindrical gap and the second cylindrical gap,

wherein the second cylindrical gap on the side that faces away from the pressurized gas supply opens into the volume for receiving the medium to be measured and the measuring device is configured such that the pressurized gas flows out through the first cylindrical gap.

2. The measuring device is claimed in claim 1 , wherein:

the volume is rotationally symmetrical,

the second part is rotationally symmetrical,

the first part has a hollow-cylindrical portion,

the second part has a cylindrical portion, and

the hollow-cylindrical portion and the cylindrical portion form a cylindrical gap.

3. The measuring device as claimed in claim 1 , further comprising a drive to provide the rotating movement, which rotating movement comprises an oscillating movement.

4. The measuring device as claimed in claim 3 , wherein the drive is configured such that the oscillating movement has a sinusoidal oscillation.

5. The measuring device as claimed in claim 4 , wherein the drive is configured such that the oscillating movement has a frequency between 0.01 Hz and 100 Hz.

6. The measuring device as claimed in claim 4 , wherein the drive is configured such that the oscillating movement has an amplitude between 5*10 −5 ° and 45°.

7. The measuring device as claimed in claim 1 , wherein:

the measuring device has a torque sensor, and

the torque sensor is provided on one of the first part and the second part.

8. The measuring device as claimed in claim 7 , wherein:

one of the first part and the second part is fixed in relation to a reference point, and

the torque sensor is provided on the fixed one of the first part and the second part.

9. The measuring device is claimed in claim 1 , wherein the pressurized gas supply is provided on the first part.

10. The measuring device as claimed in claim 9 , wherein the first cylindrical sleeve portion and the second cylindrical sleeve portion of the first part and the pressurized gas supply conjointly form a unit which is capable of being separated from a cup of the first part that is provided for receiving the medium to be measured.

11. The measuring device as claimed in claim 1 , wherein the measuring device has a first device, and the volume for receiving the medium to be measured is capable of being temperature controlled by way of the first device.

12. The measuring device is claimed in claim 11 , wherein the temperature control device has a Peltier element which is conceived and disposed in such a manner so as to control the temperature of the volume for receiving the medium to be measured.