Abstract: A slurry container for use in a consistometer to test a cement slurry includes a cup and a sealed pressure communicating structure. The sealed pressure communicating structure includes a baffle plate, a thermocouple well threadedly connected to an internal surface of a neck portion of the baffle plate, and a diaphragm extending radially between an outer surface of the neck portion of the baffle plate and an inner surface of the cup and longitudinally between facing surfaces of the baffle plate and a flange of the thermocouple well. A paddle is mounted on a shaft which is pivoted between the lower end of the thermocouple well and the bottom of the cavity defined in the cup. Magnets are mounted on the paddle to provide magnetic coupling across the sealed boundary defined by the baffle plate, thermocouple well and diaphragm assembly.