ASTM D3321-94(2007)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D3321–94 (Reapproved 2007)
Standard Test Method for
Use of the Refractometer for Field Test Determination of the
Freezing Point of Aqueous Engine Coolants
This standard is issued under the fixed designation D3321; 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.
1. Scope propylene glycol coolant freezing point protection. Only a few
drops of test solution are required. Some testers automatically
1.1 This test method covers the use of a portable refracto-
correct for ambient air temperature and the temperature of the
meter for determining the approximate freezing protection
solution being tested.The instrument is rugged, simple to read,
provided by ethylene and propylene glycol-based coolant
and easy to clean and maintain.
solutions as used in engine cooling systems and special
3.2 The coolant freezing point readings are taken at points
applications.
where the dividing line between light and dark crosses the
NOTE 1—Some instruments have a supplementary freezing protection
scales. Some refractometers have a coolant scale for indicating
scale for methoxypropanol coolants. Others carry a supplemental scale
the freezing point of aqueous ethylene glycol coolants only,
calibrated in density or specific gravity readings of sulfuric acid solutions
while other refractometers also have a scale for indicating the
so that the refractometer can be used to determine the charged condition
freezing point of aqueous propylene glycol coolants.The range
of lead acid storage batteries.
of the scales varies from one device to another.
1.2 The values stated in SI units are to be regarded as the
3.3 Freezing point measurements are concentration-related
standard. The values given in parentheses are for information
values and are in turn directly related to refractive index. It has
only.
been empirically determined that freezing point measurements
1.3 This standard does not purport to address all of the
are accurate within 1°C (2°F).
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Significance and Use
priate safety and health practices and determine the applica-
4.1 This practice is commonly used by vehicle service
bility of regulatory limitations prior to use.
personnel to determine the freezing point, in degrees Celsius or
Fahrenheit, of aqueous solutions of commercial ethylene and
2. Referenced Documents
propylene glycol-based coolant. A durable hand-held refracto-
2.1 ASTM Standards:
meter is available that reads the freezing point, directly, in
D1177 Test Method for Freezing Point of Aqueous Engine
degrees Celsius or Fahrenheit, when a few drops of engine
Coolants
coolant are properly placed on the temperature-compensated
prism surface of the refractometer. This refractometer is for
3. Summary of Test Method
glycol and water solutions, and is not suitable for other coolant
3.1 These coolant testers are critical-angle refractometers
solutions.
designed for rapid, approximate measurement of ethylene and
4.2 The hand-held refractometer should be calibrated before
use (see Section 7).
This test method is under the jurisdiction ofASTM Committee D15 on Engine
4.3 Care must be taken to use the correct glycol freezing
Coolants and is the direct responsibility of Subcommittee D15.03 on Physical
point scale for the glycol type being measured. Use of the
Properties.
Current edition approved Nov. 15, 2007. Published November 2007. Originally wrong glycol scale can result in freezing point errors of 18 and
approved in 1974. Last previous edition approved in 2002 as D3321 – 94(2002).
more degrees Fahrenheit.
DOI: 10.1520/D3321-94R07.
4.4 Ethylene glycol/propylene glycol mixtures will result in
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
inaccurate freezing point measurements using either freezing
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
point scale.
the ASTM website.
Coolant testers are available from Leica Inc., P.O. Box 123, Buffalo, NY14240
and Misco Products, 3401 Virginia Rd., Cleveland, OH 44122.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3321–94 (2007)
5. Interferences
5.1 Interference can occur if the mixture is contaminated or
if the prism surface is not clean. The presence of other glycols
such as diethylene glycol in small amounts will not cause
interference.
6. Apparatus
6.1 The hand-held critical angle refractometer is a rugged
die-cast portable instrument that is covered with a high-impact
plastic to minimize damage to the eyepiece lens if dropped. A
polished glass prism is opposite the viewing end. A hinged
plastic cover is moved over the prism (sampling end) to allow
for even sample distribution and prevent liquid sample spillage
during the test. No eyepiece or prism adjustments are required
for sample testing.
6.2 The telescopic recessed eyepiece is located at one end
and the graduated, translucent prism on the opposite end (see
Fig. 1).
7. Calibration
7.1 Calibration of these coolant testers should periodically
be verified by testing a water sample in accordance with the
procedure outlined in Section 8.
7.2 If the sample tested deviates from 0°C (+32°F) the
coolant tester is out of calibration and should be recalibrated.
7.3 This calibration test is best performed with the coolant
tester and water sample at room temperature. If th
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