Abstract: A method of determining viscosity of structurally viscous fluids or beverages containing small pieces, fibers, pulps, fruit cells, cereals, particles or the like, for processing in filling, fruit juice preparation, dairy or brewery process plants, includes providing a tube rheometer having an at least substantially horizontal, straight meter tube with an inner diameter over a length of the meter tube length. At least two different volume flows are generated, exclusively gravimetrically, in the tube rheometer. The at least two different volume flows are adjusted to be substantially constant so as to determine a flow index and a consistency factor of the at least two volume flows. Pressure losses of the at least two volume flows are measured. The viscosity is determined based on the flow index, the consistency factor and the pressure losses.

Abstract: A method for testing the integrity of a hollow fibre membrane includes inserting a sterile, monomolecular gas into an interior of the hollow fibre membrane, applying a starting gas pressure on the gas in the interior of the hollow fibre membrane at a first point in time, and measuring the pressure of the gas at a second point in time after the first point in time so as to determine a final gas pressure.

Abstract: A method of determining viscosity of structurally viscous fluids or beverages containing small pieces, fibers, pulps, fruit cells, cereals, particles or the like, for processing in filling, fruit juice preparation, dairy or brewery process plants, includes providing a tube rheometer having an at least substantially horizontal, straight meter tube with an inner diameter over a length of the meter tube length. At least two different volume flows are generated, exclusively gravimetrically, in the tube rheometer. The at least two different volume flows are adjusted to be substantially constant so as to determine a flow index and a consistency factor of the at least two volume flows. Pressure losses of the at least two volume flows are measured. The viscosity is determined based on the flow index, the consistency factor and the pressure losses.