Operating Manual for R-S Rheometer

I. General Description

In this chapter you get general information concerning use and measurement principle of your R/S Rheometer.

I.1 Use of the Rheometer

The R/S Rheometer system provides possibility of Newtonian fluids viscosity measurements, recording of flow curves as well as determination of viscosity functions of non-Newtonian fluids in steady shear flows. Furthermore, it assures carrying out of measurements in non-stationary shear flows and the measurements of viscoelastic substances values in creep processes. The R/S Rheometer is used in quality control, production control and researches

I.2 Measuring Principle

The R/S Rheometer is a rotational-shear rate /shear stress-rheometer.

Concentric cylinders, measuring cones and plates are available as measuring system. The measuringsample is positioned in measuring gap between the stationary measuring cup and the rotating measuring bob (Searle-principle), respectively between the rotating cone or plate and the stationary lower plate (cone/plate-, cone/cone-measuring-system).

The measuring drive developed for this instrument operates with a high dynamic precision-drive- system with optical encoder without gearing and without mechanical force transducers, so torque is measured without deflection.

The R/S Rheometer measuring drive is applicable for carrying out rotational measurements with pre-set of speed (shear rate) and pre-set of torque (shear stress).

In case of shear rate pre-set the torque acting on rotating measuring bob/cone/plate by measuring substance flow resistance is measured (shear stress is measured).

In case of shear stress pre-set resulting speed of rotating measuring bob/cone/plate is measured (shear rate).

Shear stress measurements can be carried out with R/S Rheometer in order to determine flow behavior of plastic substances and enables exact measurement of yield point without shearing the measuring substance.

The types of measurements

-rotation measurement with controlled shear rate (CSR)

-rotation measurement with controlled shear stress (CSS)

can be carried out in manual (without PC support) or in connection with a computer system with the software RHEO 2000.

The creep measurements requires computer system with software RHEO 2000.

II. System Configuration

In this chapter you get information concerning system configuration, temperature control device, optional computer system and dataand signal flow of your Rheometer system.

The Rheometer system R/S Rheometer consists of:

-electronic unit with measuring drive integrated in one housing

-stand with working surface

-AC-adaptor

as accessories are supplied:

•printer

•coaxial cylinder measuring system (see Appendix A)

•temperature measuring sensor Pt100

•standard measuring device ME-CP/PP for cone/plate and plate/plate measuring systems

•cone/plateand plate/plate measuring systems

•temperature control device “FTK-CC“

•cooling device “KE“

•fluids circulation thermostat

•computer system

•software RHEO 2000

bold printed accessories are necessary for minimal configuration

II.1 R/S Rheometer

The Rheometer electronics with measuring drive are built-in in one housing.

The R/S Rheometer system can serve due to consequent use of microelectronics with special capacities:

digital control of rotational speed and torque

automatic matching of control parameters during measurement

direct indication of measured and calculated values of speed, shear rate, torque, shear stress, viscosity, temperature, time etc.

internal measuring values storage

measuring values output to a printer (parallel centronics)

user support by dialog mode at LCD-display with clear text output

built-in system interface with serial standard interface (RS-232-C) for the direct connection of a computer or other serial data-loggers.

printing and serial data-transmission while measuring possible

The R/S Rheometer is operated manually using foil keyboard at the front panel or under computer control. The power supply of the R/S Rheometer with direct current is carried out by AC-adaptor.

II.2 Measuring Devices

Measuring devices are not included in the main delivery volume of R/S Rheometer and must be ordered in accordance with your measuring requirements.

As measuring devices are optional supplied:

•coaxial standard measuring systems for R/S Rheometer (see Appendix A) with and without built-in temperature sensor Pt100

•temperature control device “FTK-CC“ for use of cylinder measuring system in temperature range -10°C ... +90°C

•cooling device “KE“ for use of cylinder measuring system in temperature range -20°C ... +180°C

•measuring device “ME-CP/PP“ for use of cone/plate or plate/plate measuring systems (see Appendix A) in temperature range -10°C ... +90°C

II.3 Computer System

The computer system is optional and provides automatic measuring, graphical representation of measuring results, printing of report as well as analysis of measuring data and quality control.

The computer system consists of:

•IBM-compatible PC with the following minimal system requirements:

-CPU 486 DX2 66 MHz

-8 MB RAM (main memory)

-10 MB free hard disk drive capacity

-operating system Microsoft Windows version 3.x, Microsoft Windows 95 or Microsoft Windows 98

-mouse and keyboard

-VGA-graphic card and monitor

-1 free serial interface RS-232

•Printer

•user software program package RHEO 2000

Fig. 1.: Computer system for R/S Rheometer

III. Instrument Installation

In this chapter you will know how to prepare your R/S Rheometer for the first measurements.

You will know particularly,

-how to mount the R/S Rheometer,

-details about the electric connections

-installation of accessories such as temperature control device, cooling device, measuring system

-hose connections.

III.1 Stand Mounting

The stand consists of:

-the stand base plate

-the stand column with Rheometer

-the shelf

Hex-nut wrench size 6 and bolt DIN 912 M8x40 are supplied for mounting.

1.The stand column is joined with the stand base plate by the supplied bolt. It is necessary to check during this operation that the parallel pin at the down side of the stand column fits into the corresponding drilled hole at the base plate.

2.Lay the shelf on the stand base plate.

Rheometer

Fig. 2.: R/S Rheometer (minimum configuration)

Hints for height adjustment of the stand:

III.2 Electrical Connections

Connections for the electrical components of the R/S Rheometer are located at the instrument back side:

Any cables from and to R/S Rheometer can be connected or disconnected only when instrument is switched off!

III.2.1 Temperature Sensor Pt100

The connecting cable of the temperature sensor Pt100 is inserted into connector “Pt100“ at the back side of the R/S Rheometer.

The Pt100 used is dependent upon measuring system device.

If you use standard cylindric measuring cups (MB-CC45...CC8) for measurements, put the sensor Pt100 into Pt100 clamp fixture and fix it parallel to the measuring system at mounting flange of the R/S Rheometer with the help of knurled-head screw.

Fig. 3: Pt100 connection and mounting

Insert the plug of Pt100 temperature sensor into the connector “Pt100” at the back side of the Rheometer.

As the viscosity is a function of the temperature, the temperature should be measured preferly in the measuring substance. For this purpose, the standard measuring systems CC45...CC8 DIN can be equipped with a Pt100 in measuring cup bottom (only in connection with FTK-CC). If you use a measuring system with built-in Pt100, insert the cable “VK-MB“ there. With this option you can measure the substance temperature directly.