5.1.1 The apparatus shall be a dead-weight piston plastometer
consisting of a thermostatically controlled heated steel
cylinder with a bore that contains a die at the lower end, and a
weighted piston operating within the cylinder. The essential
features of the plastometer, illustrated in Figs. 1 and 2, are
described in 5.2-5.12. The bore of the extrusion plastometer
shall be properly aligned in the vertical direction (see Appendix
X1). All dimensional measurements shall be made when the
article being measured is at 23 6 5°C.