Standard Test Method for Consistency of Paints Measuring Krebs Unit (KU) Viscosity Using a Stormer-Type Viscometer

SIGNIFICANCE AND USE
This test method provides values that are useful in specifying and controlling the consistency of paints, such as consumer or trade sales products.
SCOPE
1.1 This test method covers the measurement of Krebs Unit (KU) viscosity to evaluate the consistency of paints and related coatings using the Stormer-type viscometer.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

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30-Nov-2005
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ASTM D562-01(2005) - Standard Test Method for Consistency of Paints Measuring Krebs Unit (KU) Viscosity Using a Stormer-Type Viscometer
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D562–01(Reapproved2005)
Standard Test Method for
Consistency of Paints Measuring Krebs Unit (KU) Viscosity
Using a Stormer-Type Viscometer
This standard is issued under the fixed designation D562; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 5. Significance and Use
1.1 This test method covers the measurement of Krebs Unit 5.1 This test method provides values that are useful in
(KU)viscositytoevaluatetheconsistencyofpaintsandrelated specifying and controlling the consistency of paints, such as
coatings using the Stormer-type viscometer. consumer or trade sales products.
1.2 The values stated in SI units are to be regarded as the
METHOD A
standard. The values given in parentheses are for information
only. 6. Apparatus
1.3 This standard does not purport to address all of the
6.1 Viscometer, Stormer, with the paddle-type rotor as
safety concerns, if any, associated with its use. It is the
illustrated in Fig. 1 and Fig. 2. The stroboscopic timer
responsibility of the user of this standard to establish appro-
attachment in Fig. 1 can be removed and the instrument used
priate safety and health practices and determine the applica-
without it but with a sacrifice of speed and accuracy. The
bility of regulatory limitations prior to use.
stroboscopic timer gives the 200 r/min reading directly.
6.2 Container, 500-mL (1-pt), 85 mm (3 ⁄8 in.) in diameter.
2. Referenced Documents
6.3 Thermometer—An ASTM Stormer Viscosity thermom-
2.1 ASTM Standards:
eter having a range from 20 to 70°C and conforming to the
E1 Specification for ASTM Liquid-in-Glass Thermometers
requirements for Thermometer 49C, as prescribed in Specifi-
cation E1.
3. Terminology
6.4 Stopwatch, or suitable timer measuring to 0.2 s.
3.1 Definitions of Terms Specific to This Standard:
6.5 Weights, a set covering the range from 5 to 1000 g.
3.1.1 consistency, n—load in grams to produce a rotational
frequency of 200 r/min (Stormer Viscometer)
7. Materials
3.1.2 Krebs units (KU), n—values of a scale commonly
7.1 Two standard oils, calibrated in absolute viscosity
used to express the consistency of paints generally applied by
(poise), that are within the viscosity range of the coatings to be
brush or roller.
measured. These oils should differ in viscosity by at least 5 P.
3.1.2.1 Discussion—This scale is a function of the “load to
NOTE 1—The normal range of the Stormer is covered by oils having
produce 200-r/min” scale.
viscosities of 4 P (70 KU), 10 P (85 KU), and 14 P (95 KU).
4. Summary of Test Method
7.1.1 Suitable standards are silicone, hydrocarbon, linseed,
4.1 The load required to produce a rotational frequency of and castor oils. Silicone and hydrocarbon oils calibrated in
200 r/min for an offset paddle rotor immersed in a paint is poises are commercially available. Uncalibrated linseed and
determined. castor oils may be calibrated with any apparatus that provides
measurements of absolute viscosity.
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.24 on Physical Properties of Liquid Paints & Paint Materials.
Current edition approved Dec. 1, 2005. Published December 2005. Originally
approved in 1947. Last previous edition approved in 2001 as D562 – 01. DOI:
10.1520/D0562-01R05.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D562–01 (2005)
L 5 ~610O 1 906.6 D!/30
where:
O = viscosity of oil in poises and
D = density of oil.
8. Calibration
8.1 Remove the rotor and weight carrier from the viscom-
eter. Make sure the string is wound evenly on the drum and
does not overlap itself.
8.2 Attach a 5-g weight onto the string and then release the
brake. If the viscometer starts to run from this dead start and
continuestorunthroughseveralrevolutionsofthestringdrum,
it is satisfactory for use. If it does not start unaided when the
5-g weight is applied, the instrument should be reconditioned.
8.3 Check the dimensions of the paddle-type rotor. They
shouldbewithin0.1mm(60.004in.)ofthedimensionsshown
in Fig. 2.
8.4 Select two standard oils having assigned values of load
to produce 200 r/min within the range of the values expected
for the coatings to be measured (see 7.1).
8.5 Adjust the temperature of the standard oils to 25 6
FIG. 1 Stormer Viscometer with Paddle-Type Rotor and
0.2°C. The temperature of the Stormer apparatus should be the
Stroboscopic Timer
same. If the specified temperature cannot be obtained, record
the temperature of the oil at the beginning and end of test to
0.2°C.
8.6 Determine the load in grams to produce 200 r/min with
each of the two oils, using either Procedure A described in
Section 9 or Procedure B described in Section 10.
8.6.1 Iftheoiltemperaturewasnotat25 60.2°Cduringthe
test, correct the measured load in grams for the deviation from
that temperature.
NOTE 2—Load corrections for deviations of oil temperature from the
specified temperature can be made by means of a previously established
plot of load versus oil temperature (see Appendix X1).
8.7 If the measured load (corrected for any temperature
deviation from standard) is within 615 % of the assigned load
values for the oils, the Stormer apparatus can be considered to
be in satisfactory calibration.
9. Procedure A (Without Stroboscopic Attachment)
9.1 Thoroughly mix the sample and strain it into a 500-mL
(1-pt) container to within 20 mm ( ⁄4 in.) of the top.
9.2 Bring the temperature of the specimen to 25 6 0.2°C
and maintain it at that temperature during the test. The
temperature of the Stormer apparatus should be the same.
9.2.1 Ifthespecifiedtemperaturecannotbeobtained,record
the temperature of the specimen at the beginning and end of
test to 0.2°C.
NOTE 1—1 in. = 25.4 mm.
9.3 When the temperature of the specimen has reached
FIG. 2 Paddle-Type Rotor for Use With Stormer Viscometer
equilibrium, stir it vigorously, being careful to avoid entrap-
ping air, and place the container immediately on the platform
7.1.2 Assignavalueofloadtoproduce200r/mintoeachoil
of the viscometer so that the paddle-type rotor is immersed in
by converting its viscosity value in poises to load in grams by
the material to the mark on the shaft of the rotor.
the following equation:
3 4
Geddes, J. A., and Dawson, D. H., “Calculation of Viscosity From Stormer Jackson,C.F.,andMadson,W.H.,“AMethodfortheStandardizationofKrebs
Viscosity Data,” Industrial and Engineering Chemistry, Vol 34, 1942, p. 163. Modified Stormer Viscometers,” ASTM Bulletin, No. 161, 1949.
D562–01 (2005)
9.4 Place weights on the hanger of the viscometer and
determine a load that will produce 100 revolutions in the range
of 25 to 35 s.
9.5 Using the information gained in 9.4, select two loads
that will provide two different readings (time to give 100
FIG. 4 Stroboscopic Lines Appearing as Multiples that May be
revolutions) within the range of 27 to 33 s. Make these
Observed Before 200-r/min Reached
measurements from a running start, that is, permit the rotor to
make at least 10 revolutions before starting the timing for 100
revolutions.
11.2 Procedure B:
9.6 Repeat the measurements outlined in 9.5 until two
11.2.1 If desired, determine from Table 2 the KU value
readings for each load are obtained that agree within 0.5 s.
corresponding to the load to produce 200 r/min.
10. Procedure B (With Stroboscopic Timer)
12. Report
10.1 Follow ProcedureA(9.1-9.3) for the preparation of the
12.1 Report the following information:
specimen.
12.1.1 The load in grams to produce 200 r/min (100
10.2 Connect the lamp circuit of the stroboscopic attach-
revolutions in 30 s),
ment to an electrical power source.
12.1.2 The calculated KU,
10.3 Place weights on the hanger of the viscometer and
12.1.3 The temperature of the specimen during the test and
determine a load that will produce 100 revolutions in the range
whether a correction was applied for any deviation from 25°C,
from 25 to 35 s.
and
10.4 Using the information gained in 10.3, select a weight
12.1.4 Whether Procedure A or Procedure B was used.
(tothenearest5g)thatwillproducethe200-r/minpattern(Fig.
3) on the stroboscopic timer, that is, where the lines appear to
be stationary. 13. Precision and Bias
10.4.1 Lines moving in the direction of paddle rotation
13.1 Precision—On the basis of a study in which determi-
indicate a speed greater than 200 r/min and therefore, weight
nations were made on five paints by two operators at each of
should be removed from the hanger. Conversely, lines moving
five laboratories on each of two different days; the within-
opposite to direction of paddle rotation indicate a speed less
laboratory coefficient of variation was found to be 3 % in load
than 200 r/min and weight should be added.
grams or 1.5 % in KU, and the between-laboratory coefficient
of variation was found to be 10 % in load grams or 4 % in KU.
NOTE 3—There are other patterns that appear at speeds other than 200
13.1.1 The following criteria should be used for judging the
r/min (See Fig. 4). The pattern for 200 r/min should be determined before
running any tests.
acceptability of results at the 95 % confidence level.
13.1.1.1 Repeatability—Two results each the mean of two
10.5 Repeat the determination in 10.4 until a consistent
measurements, obtained on the same material by the same
value of load is obtained (that is, to within 5 g).
operator at different times should be considered suspect if they
differ by more than 1.7 % in KU.
11. Calculation
13.1.1.2 Reproducibility—Two results, each the mean of
11.1 Procedure A:
two measurements on the same material, obta
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