BS EN ISO 5530-2:2015 pdf free
BS EN ISO 5530-2:2015 pdf free.Wheat flour一Physical characteristics of doughs
Some workers prefer to measure the height of the curve at a fixed extension of the test piece, usually corresponding to 50 mm transposition of the recorder paper. The extension is measured from the moment that the hook touches the test piece; i.e. when the force is suddenly different from zero.
Take as the result of the resistance to stretching at constant deformation, R5o, the mean of the heights of the extensograph curves after 50 mm transposition of the recorder paper (see Figure 1) from the two test pieces,provided that the difference between them does not exceed 15 % of their mean value.
Report each of the mean values of R50,45, R5o ,90 and R50,135 to the nearest 5 EU.Owing to the greater depression of the cradle, a more resistant test piece is extended to a lesser extent at 50 mm transposition of the recorder paper than a less resistant test piece. It is possible, by means of a suitable template, to read the resistances of all test pieces at the same net extension. If such a template is used, it is necessary to mention this in the test report.
The extensibility, E, is the distance travelled by the recorder paper from the moment that the hook touches the test piece until rupture of (one of the strings of) the test pieces. Rupture is indicated on the extensograph curve either by a smooth fall of the curve almost to zero force, or by a sharp break in the curve (see Figure 1).
Beyond the breaking point, the course of the recording depends on the inertia of the lever system and on the time interval between the breaking of the two strings of the test piece. For measurement of the extensibility, the curve is supposed to proceed, from the breaking point, along a circular ordinate line (dashed line in Figure 1) down to zero force. To identify the breaking point on the curve properly, it is necessary to observe the test piece when breaking.
Take as the result of the extensibility the mean distance on the extensograph curves from the two test pieces,provided that the difference between them does not exceed 9 % of their mean value.Report each of the mean values of E45, Ego and E135 to the nearest millimetre.BS EN ISO 5530-2 pdf downlaod.