Introduction - Ametek BROOKFIELD RSO Operating Instructions Manual

RSO
™
Operator Instructions

1. INTRODUCTION

The Brookfield RSO Rheometer is a rotational and oscillatory controlled-stress rheometer used
in quality control, product development, and research. The measuring drive developed for this
instrument utilizes a high precision dynamic drive system with an optical encoder for absolute position
measurement of spindle deflection.
There are four basic methods of measurement available with the RSO Rheometer:
• Rotational measurement under controlled shear rate (CSR)
• Rotational measurement under controlled shear stress (CSS)
• Oscillatory measurement under controlled shear stress (CSS)
• Oscillatory measurement under controlled deformation/strain (CD)
The RSO Rheometer has all the functionality of a standard Brookfield rotational viscometer,
performing rotational tests with pre-set speed or shear rate. The RSO Rheometer is even more
versatile because it can also perform tests with a pre-set torque or shear stress and measure the
resulting shear deformation of the test substance via angular deflection of the measuring element.
The RSO controlled stress capabilities can be used for experiments such as:
(1) Measurement of the "static" yield stress – eliminating the multi-shear rate test that requires
math model extrapolation; and
(2) Creep and Recovery of numerous materials.
Additionally, the RSO Rheometer is equipped with a powerful motor with a usable torque range of
0.005 to 100 milliNewton-meters, mN-m or mNm. As a result, the RSO Rheometer is appropriate for
rheological measurements over a wide range of sample viscosities. Furthermore, the oscillatory mode
measures viscoelastic material responses that cannot be measured in rotational tests. One advantage
of small-amplitude oscillatory rheometry or "SAOS" is that the small strains or deformations can
probe weak structures without destroying them (e.g., testing weak gels, etc.)
The Brookfield RSO Rheometer incorporates the following features:
• Air-bearing, drag cup motor, capable of both rotational and oscillatory measurements.
• Digital control of rotational speed, shear rate, torque, or shear stress.
• Pre-designed rotational measurement programs for analysis of viscosity flow curves, creep
and recovery behavior, yield stress, and thixotropic properties.
• Pre-designed oscillatory test methods: amplitude sweep, frequency sweep, time-dependent
or temperature-dependent behavior.
M19-230-REV.B
© 2020 AMETEK Brookfield Inc. All rights reserved.
Page 6