STRAIN VIEWER Specification:  Viewing field:..............260 x 260mm Overall size: ...............445 x 280 x 280mm Mains voltage:............220/240v The advantages of our PET preform strain viewer are: 1.    Crystallinity is readily identified. 2.    Not only can the molecular birefringent flow lines (fringes) be seen in colour, but also the black isoclinic lines are visible when the preform axis are parallel to the polarising axis of the viewer. The isoclinic lines indicate the directions of the molecular orientational strains. 3.    A special and removable stage is provided to rapidly obtain the correct alignments of the preforms when viewing. For observations of the fringes the preforms are aligned at 45 degrees to the polarising axis and at 0 degrees to view the black isoclinics. The stage allows for the rotation of the preforms whilst viewing. Sodium light is also provided, in addition to white light, for the examination of coloured preforms or completed bottles.