Brookfield DV3T Rheometer - Manual (Page 107)

Brookfield Engineering Labs., Inc. Page 107 Manual No. M13-2100
Brookfield Viscosity Standard Fluid General Information
We recommend that Brookfield Viscosity Standard Fluids be replaced on an annual basis, one
year from date of initial use. These fluids are pure silicone and are not subject to change over
time. However, exposure to outside contaminants through normal use requires replacement on
an annual basis. Contamination may occur by the introduction of solvent, standard of different
viscosity or other foreign material.
Viscosity Standard Fluids may be stored under normal laboratory conditions. Disposal should be
in accordance with state, local and federal regulations as specified on the material safety data sheet.
Brookfield Engineering Laboratories does not recertify Viscosity Standard Fluids. We will issue
duplicate copies of the Certificate of Calibration for any fluid within two years of the purchase
date. Brookfield Viscosity Standard Fluids are reusable provided they are not contaminated.
Normal practice for usage in a 600 mL beaker is to return the material from the beaker back into
the bottle. When using smaller volumes in accessories such as Small Sample Adapter, UL Adapter
or Thermosel, the fluid is normally discarded.
Calibration Procedure for LV #1-3 (#61-63) and RV, HA, HB #1-6 Brookfield Spindles
Please note that the LV #4 (64) and RV, HA, HB #7 (07) spindles have been omitted from this
procedure. Brookfield does not recommend the use of these spindles to perform a calibration
check on your instrument. Reasons pertain to the small amount of spindle surface that
makes contact with the viscosity standard, the difficulty of establishing the immersion mark
precisely and the need for precise temperature control at 25°C in the immediate vicinity of
the spindle.
Follow these steps using one of the recommended spindles to verify calibration on your instrument:
1) Place the viscosity standard fluid (in the proper container) into the water bath.
2) Lower the DV3T into measurement position (with guard leg if LV or RV series Rheometer
is used).
3) Attach the spindle to the Rheometer. If you are using a disk-shaped spindle, avoid trapping
air bubbles beneath the disk by first immersing the spindle at an angle, and then connecting
it to the Rheometer.
4) The viscosity standard fluid, together with the spindle, should be immersed in the bath for
a minimum of 1 hour, stirring the fluid periodically, prior to taking measurements.
5) After 1 hour, check the temperature of the viscosity standard fluid with an accurate
thermometer.
6) If the fluid is at test temperature (±0.1°C of the specified temperature, normally 25°C),
measure the viscosity and record the Rheometer reading. Note: The spindle must rotate at
least five (5) times before readings are taken.
7) The viscosity reading should equal the cP value on the fluid standard to within the combined
accuracies of the Rheometer and the viscosity standard (as discussed in the section, at the
end of this Appendix, entitled Interpretation of Calibration Test Results) which appears
later in this section.