Table of Contents
Advertisement
4. MAKING YIELD MEASUREMENTS
4.1 Quick start
The DVNext Rheometer uses the same methodology for yield measurements as the AMETEK Brookfield YR-1 and
DV-III Ultra Rheometers. If you have experience with other AMETEK Brookfield equipment, this section will give you
quick steps for making a yield measurement. If you have not used a AMETEK Brookfield Rheometer before, skip this
section and go to (Section 4.2) for a detailed description.
•
Assemble and level the DVNext Rheometer (Section 1.4).
•
Turn power on.
•
Autozero the rheometer (Section 2.2).
•
The DVNext will display the Configure Viscosity Test Screen. Press the Home Icon in the Navigation Bar.
From the Home Menu, select Configure Yield Test.
•
Select: Spindle, Immersion Mark, and Run Speed.
•
Attach the vane spindle to the DVNext.
•
NOTE: If equipped with magnetic coupling, use the appropriate procedure to connect the spindle (see
Section III.3). Immerse the spindle gently into the test sample by lowering the DVNext on the Model G
laboratory stand.
•
Press the Run button. The screen will change to the Running Yield Test Screen.
•
When the Yield Test is complete, the DVNext will present the Yield Test Complete screen. Record the
Stress (yield stress), Torque, and Temperature.
•
To run another test, press Configure Test. To return to the Home Menu, press the Home Icon.
4.2 Preparations for making measurements
A
RHEOMETER: The DVNext should be turned on, leveled and autozeroed. The level is adjusted using
the two feet on the bottom of the base and confirmed through aligning the digital bubble on the
screen with the center of the leveling circle. Adjust the feet until the bubble is inside the center
target. Set the level prior to autozero.
The proper level is essential for correct operation of the DVNext.
B
Sample: The measured yield value is very dependent on how the sample is handled prior to the
measurement. The sample should be disturbed as little as possible prior to inserting the vane
spindle. AMETEK Brookfield recommends testing the sample in the container in which it is provided
when possible. If it is necessary to transfer the sample to a new container, then it is recommended
to include a pre-shear and/or wait time in the Yield Test. This pre-shear and wait time will provide a
common history to each sample to aid in sample to sample comparison.
AMETEK Brookfield recommends the use of vane spindles for measuring yield value. The vane spindle provides a
unique geometry that minimizes disturbance of the sample during spindle insertion.
Many samples must be controlled to a specific temperature for yield measurement.
When conditioning a sample for temperature, be sure to temperature control the contrainer and spindle as well as the
sample.
M19-2101 REVISION 2.0
D V N E X T R H E O M E T E R - O P E R AT I O N A L M A N U A L
51
Advertisement
Table of Contents
