ASTM D5482-20a

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of the standard as published by ASTM is to be considered the official document.
Designation: D5482 − 20 D5482 − 20a
Standard Test Method for
Vapor Pressure of Petroleum Products and Liquid Fuels
(Mini Method—Atmospheric)
This standard is issued under the fixed designation D5482; 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*
1.1 This test method covers a procedure for the determination of total vapor pressure of petroleum products and liquid fuels
using automatic vapor pressure instruments. The test method is suitable for testing samples with boiling points above 0 °C (32 °F)
that exert a vapor pressure between 7 kPa and 110 kPa (1.0 psi and 16 psi) at 37.8 °C (100 °F) at a vapor-to-liquid ratio of 4:1. The
test method is applicable to gasolines containing oxygenates. No account is made of dissolved water in the sample.
NOTE 1—Because the external atmospheric pressure does not influence the resultant vapor pressure, this vapor pressure is an absolute pressure at
37.8 °C (100 °F) in kPa (psi). This vapor pressure differs from the true vapor pressure of the sample due to some small vaporization of the sample and
dissolved air into the air of the confined space.
1.1.1 Some gasoline-oxygenate blends may show a haze when cooled to 0 °C to 1 °C. If a haze is observed in 8.5, it shall be
indicated in the reporting of results. The precision and bias statements for hazy samples have not been determined (see Note 6).
1.2 This test method is a modification of Test Method D5191 (Mini Method) in which the test chamber is at atmospheric
pressure prior to sample injection.
1.3 This test method covers the use of automated vapor pressure instruments that perform measurements on liquid sample sizes
in the range from 1 mL to 10 mL.
1.4 This test method is suitable for the determination of the dry vapor pressure equivalent (DVPE) of gasoline and
gasoline-oxygenate blends by means of a correlation equation (see 13.2). The calculated DVPE is considered equivalent to the
result obtained on the same material when tested by Test Method D4953.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.6 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. (For specific warning statements, see 7.2 through 7.7.)
1.7 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D4306 Practice for Aviation Fuel Sample Containers for Tests Affected by Trace Contamination
D4953 Test Method for Vapor Pressure of Gasoline and Gasoline-Oxygenate Blends (Dry Method)
D5190 Test Method for Vapor Pressure of Petroleum Products (Automatic Method) (Withdrawn 2012)
D5191 Test Method for Vapor Pressure of Petroleum Products and Liquid Fuels (Mini Method)
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.08 on Volatility.
Current edition approved May 1, 2020July 1, 2020. Published May 2020July 2020. Originally approved in 1993. Last previous edition approved in 20132020 as
D5482 – 07 (2013).D5482 – 20. DOI: 10.1520/D5482-20.10.1520/D5482-20A.
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.
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5482 − 20a
D5842 Practice for Sampling and Handling of Fuels for Volatility Measurement
D5854 Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products
3. Terminology
3.1 Definitions:
3.1.1 dry vapor pressure equivalent (DVPE), n—value calculated by a defined correlation equation, that is expected to be
comparable to the vapor pressure value obtained by Test Method D4953, Procedure A.
3.1.2 gasoline-oxygenate blend, n—spark-ignition engine fuel consisting primarily of gasoline with one or more oxygenates.
3.1.2 oxygenate, n—oxygen-containing ashless organic compound, such as an alcohol or ether, which may be used as a fuel or
fuel supplement. D4175
3.1.3 platinum resistance thermometer, n—temperature measuring device with constructed with a length of platinum wire,
whose electrical resistance changes in relation to temperature.
3.1.4 total vapor pressure, n—observed pressure measured in the experiment, that is the sum of the partial pressure of the sample
and the partial pressure of the dissolved air.
3.1.5 vapor pressure, n—pressure exerted by the vapor of a liquid when in equilibrium with the liquid. D4175
3.2 Abbreviations:
3.2.1 DVPE, n—dry vapor pressure equivalent.
3.2.2 MTBE, n—methyl t-butyl ether.
4. Summary of Test Method
4.1 A known volume of chilled, air-saturated sample is introduced into a thermostatically controlled test chamber, the internal
volume of which is five times that of the total test specimen introduced into the chamber. The test chamber is at atmospheric
pressure prior to introduction of the sample. After introduction of the sample into the test chamber, the test specimen is allowed
to reach thermal equilibrium at the test temperature, 37.8 °C (100 °F). The resulting rise in pressure in the chamber is measured
using a pressure transducer sensor and indicator.
4.2 The measured total vapor pressure is converted to a DVPE by use of a correlation equation (see 13.2).
5. Significance and Use
5.1 Vapor pressure is an important physical property of volatile liquids.
5.2 Vapor pressure is critically important for both automotive and aviation gasolines, affecting starting, warm-up, and tendency
to vapor lock with high operating temperatures or high altitudes. Maximum vapor pressure limits for gasoline are legally mandated
in some areas as a measure of air pollution control.
6. Apparatus
6.1 Vapor Pressure Apparatus—The type of apparatus suitable for use in this test method employs a small volume test chamber
incorporating a transducer for pressure measurements and associated equipment for thermostatically controlling the chamber
temperature.
6.1.1 The test chamber shall be designed to contain between 2 mL and 50 mL of liquid and vapor and be capable of maintaining
a vapor-liquid ratio between 3.95 and 1.00 and 4.05 and 1.00.
6.1.2 The pressure transducer shall have a minimum operational range from 0 kPa to 172 kPa (0 psi to 25.0 psi) with a minimum
resolution of 0.1 kPa (0.01 psi) and a minimum accuracy of 60.3 kPa (60.05 psi). The pressure measurement system shall include
associated electronics and readout devices to display the resulting pressure reading.
6.1.3 A thermostatically controlled heater shall be used to maintain the test chamber at 37.8 °C 6 0.1 °C (100 °F 6 0.2 °F) for
the duration of the test.
6.1.4 A platinum resistance thermometer shall be used for measuring the temperature of the test chamber. The minimum
temperature range of the measuring device shall be from ambient to 75 °C (167 °F) with a resolution of 0.1 °C (0.2 °F) and
accuracy of 0.1 °C (0.2 °F).
6.1.5 The vapor pressure apparatus shall have provisions for introduction of the test specimen into the test chamber and for the
cleaning or purging of the chamber following the test.
The following instruments have been found satisfactory for use in this test procedure as determined by interlaboratory testing: Herzog Mini Reid Vapor Pressure Model
MP970—available from Varlen Instruments, Inc., 2777 Washington Blvd., Bellwood, IL 60104 and ABB Model 4100—available from ABB Process Analytics, Lewisburg,
WV. If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a
meeting of the responsible technical committee, which you may attend.
D5482 − 20a
6.2 Syringe, if required, gas tight, 1 mL to 20 mL capacity with a 61 %, or better, accuracy and a 61 %, or better, precision.
The capacity of the syringe shall not exceed two times the volume of the test specimen being dispensed, and shall be chosen so
as to provide maximum accuracy and resolution for the volume to be injected.
6.3 Iced-Water Bath or Air Bath, for chilling the samples and syringe to temperatures between 0 °C and 1 °C (32 °F and 34 °F).
6.4 Pressure Measuring Device, capable of measuring ambient and above ambient pressures with an accuracy of 0.20 kPa
(0.03 psi) or better at the same elevation relative to sea level as the apparatus in the laboratory.
6.4.1 When a mercury manometer is not used as the pressure measuring device, the calibration of the pressure measuring device
employed shall be periodically checked (with traceability to a nationally recognized standard) to ensure that the device remains
within the required accuracy specified in 6.4.
6.5 Pressure Source, clean, dry compressed gas or other suitable compressed air capable of providing pressure for calibration
of the transducer and cleaning of the cell.
NOTE 2—A vacuum source is an alternate means for cleaning of the cell.
7. Reagents and Materials
7.1 Purity of Reagents—Use chemicals of at least 99 % purity for quality control checks (see Section 11). Unless otherwise
indicated, it is intended that all reagents conform to the specifications of the Committee on Analytical Reagents of the American
Chemical Society where such specifications are available. Lower purities can be used, provided it is first ascertained that the
reagent is of sufficient purity to permit its use without lessening the accuracy of the determination.
7.2 Cyclohexane, (Warning—Cyclohexane is flammable and a health hazard).
7.3 Cyclopentane, (Warning—Cyclopentane is flammable and a health hazard).
7.4 2,2-Dimethylbutane, (Warning—2,2-dimethylbutane is flammable and a health hazard).
7.5 2,3-Dimethylbutane, (Warning—2,3-dimethylbutane is flammable and a health hazard).
7.6 2-Methylpentane, (Warning—2-methylpentane is flammable and a health hazard).
7.7 Toluene, (Warning—Toluene is flammable and a health hazard).
8. Sampling
8.1 General Requirements:
8.1.1 The extreme sensitivity of vapor pressure measurements to losses through evaporation and the resulting changes in
composition is such as to require the utmost precaution and the most meticulous care in the handling of samples.
8.1.2 Obtain a sample and test specimen in accordance with Practice D4057, D4177, D4306, D5842, or D5854 when
appropriate, except do not use the Sampling by Water Displacement section for fuels containing oxygenates. Use a 1 L (1 qt) sized
container filled between 70 % to 80 % with sample.
8.1.3 The present precision statement has been derived using samples in 1 L (1 qt) containers. Samples taken in containers of
other sizes as prescribed in 8.1.2 can be used if it is recognized that the precision can be affected. In the case of referee testing,
the 1 L (1 qt) sample container shall be mandatory.
8.1.4 Perform the vapor pressure determination on the first test specimen withdrawn from a sample container. Do not use the
remaining sample in the container for a second vapor pressure determination. If a second determination is necessary, obtain a new
sample.
8.1.5 Protect samples from excessive temperatures prior to testing. This can be accomplished by storage in an appropriate ice
bath or refrigerator.
8.1.6 Do not test samples stored in leaky containers. Discard and obtain a new sample if leaks are detected.
8.1.7 Do not store samples in plastic (polyethylene, polypropylene, and so forth) containers since volatile materials may diffuse
through the walls of the container.
8.2 Sampling Temperature—Cool the sample container and contents in an ice bath or refrigerator to the 0 °C to 1 °C (32 °F to
34 °F) range prior to opening the sample container. Allow sufficient time to reach this temperature. Verify the sample temperature
by direct measurement of the temperature of a similar liquid in a similar container placed in the cooling bath or refrigerator at the
same time as the sample.
8.3 Verification of Sample Container Filling—With the sample at a temperature of 0 °C to 1 °C, take the container from the
cooling bath or refrigerator and wipe dry with an absorbent material. If the container is not transparent, unseal it and using a
ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference Materials, American Chemical Society, Washington, DC. For
suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and
the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
D5482 − 20a
suitable gage, confirm that the sample volume equals 70 % to 80 % of the container capacity (see Note 3). If the sample is
contained in a transparent glass container, verify that the container is 70 % to 80 % full by suitable means (see Note 3).
8.3.1 Do not perform a vapor pressure test on the sample if the container is filled to less than 70 % by volume of the container
capacity.
8.3.2 If the container is more than 80 % by volume full, pour out enough sample to bring the container contents within the 70 %
to 80 % by volume range. Do not return any sample to the container once it has been withdrawn.
NOTE 3—For non-transparent containers, one way to confirm that the sample volume equals 70 % to 80 % of the container capacity is to use a dipstick
that has
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