Applications •Testing of viscosity, consistency or cohesion of fluidand pasty masses, e.g. joghurt, pudding, mustard, tomato paste, oils Applications •Simulates as nearly as possible, the single bite of pre-fragmented foodstuffs.•Texture characteristics of small sized fruit andvegetable products, cereals, etc. Setup and performing a test The Kramer shear cell consists of a box, which has a floor with slotted openings. The specimen material is filled into this box. The rectangular shaped cutters are affixed via guides (the Kramer shear cell is available in two options, with 5 or with 10 cutters). The cell is mounted on a basic platform so that a free space remains underneath. Here the specimen material which is pushed out can be collected. The advantage of a Kramer shear cell is that not only one position is measured, but 5 or 10 positions at the same time. Local texture deviations are compensated for with this method. The cutters drive at a constant speed through the specimen material, compressing and shearing the specimen until it is pushed through the floor of the cell. The force-path or force-time curve is the result and conclusions as to the chewing characteristic, the crispiness or the freshness can be made. Kramer shear test deviceKramer shear test The Kramer shear cell was developed in 1959 by Kramer & Twigg and it is the most widely used test method in the area of foodstuffs testing. It simulates as nearly as possible, the single bite of prefragmented foodstuffs.

1.4 Zwick Roell test devices withapplications examples

Back extrusion test deviceBack extrusion test With the back extrusion test, a die is moved up and down in a fluid test material. The measured forces at defined speeds, determine the viscosity . Setup and performing a test The back extrusion cell consists of a cylindrical container and a cylindrical compression die. The container is fixed to the machine to prevent lifting during the reverse stroke. A certain volume (min. 75 % of the container´s volume) of the test material is filled into the cell. The die pushes into the specimen with a defined speed and continues until a pre-set position has been reached. When this position has been reached, the die drives back to the beginning position. During this movement, the specimen material flows through a ring slot between the container and the piston into the other container area. The force required for this action allows the viscosity to be determined.
Picture 9: Viscosity testing of ketchup with the back extrusion test device Picture 10: Shear testing of cereals with the5-blades Kramer shear test device for determination of crispiness 9