The Helical Screw Rheometer (HSR) is being evaluated for rheological measurements of fluid food suspensions. the HSR consists of a helical screw enclosed in a tight fitting cylinder. With a closed system the inner screw is rotated creating a linearly increasing pressure differential along the axis of the screw, which is proportional to the viscosity of the fluid. This paper presents theoretical one‐ and two‐dimensional flow analyses for Newtonian fluids using both rectangular and cylindrical coordinates. For non‐Newtonian fluids a one‐dimensional rectangular analysis was developed using the power law model.

Measurements with a helical screw rheometer (HSR), which consisted of a helical screw enclosed in a tight fitting barrel, were compared with readings from a cone and plate rheometer. Comparable viscosity measurements were obtained with both instruments using carboxymethylcellulose solutions and tomato products. The HSR had the advantages that it could be more easily used for on-line measurements and was suitable for fluid food suspensions because it prevented settling or separation of particulates during the measurement.

The Helical Screw Rheometer (HSR) consists of a helical screw enclosed in a tight fitting cylinder. When the screw is rotated with the system closed it generates a linearly increasing pressure differential along the axis of the screw. The pressure is proportional to the viscosity of a Newtonian fluid. Viscosity of standard Newtonian fluids measured using the HSR correlated well with measurements on a rotational rheometer with cone and plate fixtures. HSR data on nonNewtonian suspensions analyzed with a power law model (a = my) did not agree as well with results from cone and plate fiiures on the rotational rheometer.

A pilot-scale flame sterilizer was interfaced to a microcomputer for real-time thermal process evaluation of individual cans. The computerized system used a photodetector system to synchronize data acquisition at predetermined monitoring sites. Infrared sensors were used to measure can temperatures. Also, a method to measure can surface temperature was developed for infrared sensor calibrations. Foil thermocouples were found to be the most accurate and reliable for surface temperature measurements. However, a thin gauge wire thermocouple attached to the inside of the can end surface was a more practical and economical method for sensor calibration.