Sample surface component for an instrument that measures viscosity and viscoelasticity

A fluid sample surface plate assembly component adapted for use in an instrument for measuring the viscosity of a fluid sample, said instrument including a plate fixture for holding said plate assembly, said plate fixture including a lower jaw and an opposing upper jaw spaced from said lower jaw, said lower jaw having a lower channel and said upper jaw having an upper channel, said instrument including a means for moving said jaws closer together and farther apart, said component comprising:

• (a) a lower plate including an open-top box with a floor, a lower sample surface on said floor, and a pair of opposed rails extending from said floor substantially parallel to said lower sample surface, said lower plate rails adapted for removably sliding into said lower jaw channel;
• (b) an upper plate having an open-top box sized to fit within said lower plate box, said upper plate box having an underside face, a top edge, an upper sample surface on said underside face, and a pair of opposed rails extending from said top edge parallel to said upper sample surface, said upper plate rails adapted for removably sliding into said upper jaw channel;
• (c) a plate clip having a pair of opposed lower grooves for removably receiving said lower plate rails and a pair of opposed upper grooves for removably receiving said upper plate rails, said clip temporarily holding said lower plate and said upper plate in fixed physical relationship to each other such that said sample surfaces oppose each other and are spaced apart;
• and
• (d) a means for providing access to said lower sample surface for depositing said fluid sample thereon;
• (e) said sample surfaces being adapted for contiguous registration over a contact area with a fluid sample therebetween after said clip is removed, said fluid sample being in contact with each of said sample surfaces;
• (f) said sample surfaces being textured such that, when said sample surfaces are pressed together and then pulled apart, the force of adhesion of said fluid sample to said sample surfaces is greater than the force of cohesion of said fluid sample.