Apparent Viscosity Test Apparatus: RAV-101 / RAV-101M

Overview

The Apparent Viscosity Test Apparatus forces a grease or oil sample through a capillary and measures the resulting back-pressure to calculate apparent viscosity as a function of shear rate. As pressure rises during the test, the instrument automatically switches the pressure gauge range in sequence from 0.5 MPa to 2.0 MPa to 10 MPa, and stops the pump once pressure exceeds 10 MPa. Pressure changes are captured in real time by data-acquisition software on a connected PC and displayed as a graph. Once the sample has been ejected from the capillary and the pressure reaches equilibrium, the operator captures the pressure reading with a single button press, and the software calculates apparent viscosity, shear rate, and shear stress and plots the apparent-viscosity-versus-shear-rate curve. A manually operated version, available in liquid-bath and air-bath configurations, is also offered.

Automatic Pressure Range Switching

The pressure gauge range automatically steps through 0.5 MPa, 2.0 MPa, and 10 MPa as pressure builds during the test, and the pump is automatically stopped once pressure exceeds 10 MPa to protect the system. This staged approach preserves reading accuracy across a wide pressure span without operator intervention.

PC-Based Data Acquisition and Calculation

Dedicated data-collection and transfer software imports pressure readings to a PC in real time and can display the results as graphs, including within common spreadsheet software. From the imported pressure readings and a pair of interchangeable tooth-gears, the software automatically calculates shear rate, apparent viscosity, and shear stress, and plots the apparent-viscosity and shear-rate curves.

Room-Temperature and Low-Temperature Variants

The RAV-101 operates at ordinary room temperature, while the RAV-101M adds an air-bath refrigeration unit to extend the operating range down to -20°C, suiting it to cold-weather and low-temperature grease evaluation. Both variants share the same pressure measurement, data-capture, and calculation system.

Common Specifications

Model Comparison