Viscosity and viscoelasticity measuring instrument

A viscosity and viscoelasticity measuring instrument has a cam, a follower arm, a flat spring, a plate fixture, and a removable plate assembly. The cam is a rotating circular disk with a spiral slot. A cam follower on the follower arm resides in the spiral slot so that the follower arm pivots about its fixed end as the cam rotates. The spring is attached to and collinear with the fixed end of the follower arm so that the spring pivots in the opposite direction as the follower arm. The removable plate assembly has a lower plate and an upper plate with mating sample surfaces on which test fluid is placed. The lower plate fits into a lower jaw of the plate fixture that is attached to the instrument base. The upper plate fits into an upper jaw of the plate fixture attached to the free end of the spring. A fluid is placed on the lower sample surface. The cam rotates, pushing the follower arm up, causing the spring to pivot down, and pressing the sample surfaces together. The cam is reversed, causing the spring to impart a separation force to the plates. The time it takes for the plates to separate is measured and converted to a viscosity value.