Brookfield DV-III Rheometer - Manual (Page 47)

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3) Select a viscosity standard fluid that will give viscosity readings between 10%
and 00% of full scale range. Refer to Appendix B for viscosity ranges of cone
spindles. Do not use a silicone viscosity standard fluid with a viscosity value
greater than 5000 cP with a Cone/Plate Viscometer. Brookfield offers a complete
range of mineral oil viscosity standards suitable for use with Cone/Plate Viscom-
eters as shown in Table E2. Consult with Brookfield or an authorized dealer to
determine which fluid is appropriate.
Table E2
MINERAL OIL VISCOSITY STANDARD FLUIDS
BEL Part No. Viscosity (cP) 25
°
C
B31 31
B210 210
B750 750
B1400 1,400
B2000 2,000
B11000 11,000
B20000 20,000
B80000 80,000
B200000 200,000
B420000 420,000
Interpretation of Calibration Test Results:
When verifying the calibration of the DV-III, the instrument and viscosity standard fluid error must
be combined to calculate the total allowable error.
The DV-III is accurate to ( + /-) 1% of any full scale spindle/speed viscosity range.
Brookfield Viscosity Standards Fluids are accurate to ( + /-) 1% of their stated value.
Example: Calculate the acceptable range of viscosity using RVDV-III with RV-3 Spindle at
2 RPM; Brookfield Standard Fluid 12,500 with a viscosity of 12,257 cP at 25
°
C:
1) Calculate full scale viscosity range using the equation:
Full Scale Viscosity Range [cP] = TK SMC
10,000
RPM
* *
Where: TK = 1.0 from Table D2
SMC = 10 from Table D1
Full Scale Viscosity Range = 1 10 10,000
* *
2
= 50,000 cP
The viscosity is accurate to ( + /-) 500 cP (which is 1% of 50,000)
2) The viscosity standard fluid is 12,257 cP. Its accuracy is ( + /-)1% of 12,257 or
( + /-)122.57 cP.