Before carrying out the test using a 'Button' trigger one must calibrate the plunger to acknowledge the bottom of the cell (i.e. the plate surface) as a zero position. To do this, lower the plunger. so that it is close to the bottom of the cell. Click on T.A. (in the menu bar) then CALIBRATE PROBE. Specify the distance that you want the plunger to start from each test - e.g. 60mm is suggested.
The plunger will move down and touch the watertight base plate and then move up to the specified start distance. For the comparison of results it is crucial that the test always begins at the same distance from the bottom of the cell, this distance can be programmed into the CONTROL PROBE feature. Prior to each test ensure that there is good clearance around the plunger to avid frictional effects. This can be checked by running a 'blank' test i.e. one without any sample in the cell, to ensure that plunger is not touching the sides. The plunger is then raised above the cell to allow for placement of the test sample. Place the sample into the cell. Simultaneously commence the test and pour 100ml After 180 seconds delay, the watertight screw is turned backwards, releasing the milk, and the plunger then proceeds to compress the sample. In between tests clean the plunger, watertight base plate, and the inside of the cell to remove any remaining sample, as this will cause variable results.