Brookfield DV2T Viscometer - Manual (Page 74)

Brookfield Engineering Labs., Inc. Page 74 Manual No. M13-167-B0614
Brookfield Viscosity Standard Fluid General Information
We recomm
end 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 DV2T into measurement position (with guard leg if LV or RV series
Viscometer is used).
3) Attach the spindle to the Viscometer. 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 Viscometer.
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 Viscometer 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 Viscometer 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.