Fluid viscosity characteristic measurement uses ultrasound pulses directed to particles in fluid held between moving surfaces

摘要

The rheometer comprises two concentric cylinders (5,6) between which there is a sample of the fluid under test. An ultrasound transducer is mounted outside the outer cylinder, in order to direct ultrasound pulses towards the fluid. The fluid contains particles which are reflecting for ultrasound, enabling viscosity characteristics of the fluid to be determined. The apparatus comprises a rheometer (1) and an ultrasound transducer (2) linked to a pulse generator and receiver (3). This is linked to a data collection card (4) linked to a microcomputer (7). The rheometer comprises two concentric cylinders (5,6) between which there is a sample of the fluid under test. The gap between the cylinders is between 0.5 and 1.1 mm, and the interior cylinder comprises a rotor turned by the rheometer. The transducer is a wide band piezo-polymer transducer mounted outside the outer cylinder, which serves as a stator. The fluid contains particles which are reflecting for ultrasound, and these may be a natural part of the fluid, or specifically added. The viscosity characteristics of the fluid may be determined by analysis of the signals detected by the transducer.