Boquilla de medición para la determinación de la viscosidad extensional de masas fundidas de plástico

The invention relates to a measuring nozzle for determining the extensional viscosity of plastic melts during the processing thereof, comprising a flow channel having a rectangular cross section, which, between an inlet section (1) and an outlet section (2) of respectively constant cross section, has a transition section (3), the width of which tapers hyperbolically in the flow direction. In order to create advantageous measuring conditions, the width of the transition section (3), according to the invention, widens hyperbolically, following the taper, to the width of the outlet section (2) that corresponds to the width of the inlet section (1), and the height of the transition section (4) decreases continuously from the height of the inlet section (1) to the smaller height of the outlet section (2).