ASTM D3701-23

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3701 − 17 D3701 − 23
Standard Test Method for
Hydrogen Content of Aviation Turbine Fuels by Low
Resolution Nuclear Magnetic Resonance Spectrometry
This standard is issued under the fixed designation D3701; 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 U.S. Department of Defense.
1. Scope*
1.1 This test method covers the determination of the hydrogen content of aviation turbine fuels.
1.2 Use Test Methods D4808 or D7171 for the determination of hydrogen in other petroleum liquids.
1.3 The values stated in SI units are to be regarded as standard. The preferred units are mass percent hydrogen.
1.4 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 healthsafety, health, and environmental practices and determine
the applicability of regulatory limitations prior to use. For a specific warning statement, see 6.17.1.
1.5 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:
D1322 Test Method for Smoke Point of Kerosene and Aviation Turbine Fuel
D1740 Test Method for Luminometer Numbers of Aviation Turbine Fuels (Withdrawn 2006)
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D4808 Test Methods for Hydrogen Content of Light Distillates, Middle Distillates, Gas Oils, and Residua by Low-Resolution
Nuclear Magnetic Resonance Spectroscopy
D7171 Test Method for Hydrogen Content of Middle Distillate Petroleum Products by Low-Resolution Pulsed Nuclear Magnetic
Resonance Spectroscopy
3. Terminology
3.1 Definitions:
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
D02.03 on Elemental Analysis.
Current edition approved June 1, 2017Nov. 1, 2023. Published June 2017November 2023. Originally approved in 1978. Last previous edition approved in 20122017 as
D3701 – 01D3701 – 17.(2012). DOI: 10.1520/D3701-17.10.1520/D3701-23.
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
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D3701 − 23
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
4. Summary of Test Method
4.1 A sample of the material is compared in a continuous wave, low-resolution, nuclear magnetic resonance spectrometer with a
reference standard sample of a pure hydrocarbon. The results from the integrator on the instrument are used as a means of
comparing the theoretical hydrogen content of the standard with that of the sample, the result being expressed as the hydrogen
content (percent mass basis) in the sample.
5. Significance and Use
5.1 The combustion quality of aviation turbine fuel has traditionally been controlled in specifications by such tests as smoke point
(see Test Method D1322), smoke volatility index, aromatic content of luminometer number (see Test Method D1740). Evidence
is accumulating that a better control of the quality may be obtained by limiting the minimum hydrogen content of the fuel.
5.2 Existing methods allow the hydrogen content to be calculated from other parameters or determined by combustion techniques.
The method specified provides a quick, simple, and more precise alternative to these methods.
6. Apparatus
6.1 Nuclear Magnetic Resonance Spectrometer —A low-resolution continuous-wave instrument capable of measuring a nuclear
magnetic resonance of hydrogen atoms, and fitted with:
6.1.1 Excitation and Detection Coil, of suitable dimensions to contain the test cell.
6.1.2 Electronic Unit, to control and monitor the magnet and coil and containing:
6.1.2.1 Circuits, to control and adjust the radio frequency level and audio frequency gain.
6.1.2.2 Integrating Counter, with variable time period in seconds.
6.2 Conditioning Block—A block of aluminum alloy drilled with holes of sufficient size to accommodate the test cells with the
mean height of the sample being at least 20 mm below the top of the conditioning block (see Fig. 1).
6.3 Test Cells—Nessler-type tubes of approximately 100 mL capacity with a nominal external diameter of 34 mm and a nominal
internal diameter of 31 mm marked at a distance of approximately 51 mm above the bottom of the tube by a ring around the
circumference. The variation between the internal diameters of the test cells used for the sample and reference material should not
be greater than 60.5 mm.
NOTE 1—To avoid potential difficulties with tightness when the test cell is introduced into the magnet coil, users are cautioned to avoid test cells that have
nominal external diameters that are greater than 34.2 mm.
6.4 Polytetrafluoroethylene (PTFE) Plugs for Closing Test Cells—Plugs as shown in Fig. 1 made from pure PTFE and a tight fit
in the test cells.
6.5 Insertion Rod—A metal rod with a threaded end as shown in Fig. 1 for inserting and removing PTFE plugs from test cells.
This test method has been written around the Newport Analyzer Mark IIIF (Oxford Analytical Instruments, Ltd., Oxford, England) and the details of the test method
should be read in conjunction with the manufacturer’s handbook.
This particular instrument was the only instrument available when the precision program was carried out. Any similar instrument would be accepted into the above method
provided the new instrument was adequately correlated and proved to be statistically similar. 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.
The Newport Analyzer Mark IIIF is no longer in production and was replaced by the manufacturer with the Newport 4000. The Newport 4000 model instrument has been
demonstrated to provide equivalent results to those obtained with the Mark III models which were used to generate the precision data. As of the mid-1990’s however, the
Newport 4000 instrument is no longer being manufactured by the vendor. No newer models are currently being manufactured as replacements for the Newport 4000
instrument.
D3701 − 23
NOTE 1—All dimensions are nominal values in millimetres, unless the tolerance limit is specified.
FIG. 1 Hydrogen Content of Aviation Turbine Fuels
6.6 Analytical Balance—Top pan type, capable of weighing the test cells in an upright position to an accuracy of 60.01 g.
7. Materials
7.1 Reference Standard—Dodecane, 99 % by mass minimum purity (Warning—Flammable).
8. Sampling
8.1 Take a homogenous sample in accordance with Practice D4057.
9. Preparation of Apparatus
9.1 Read the following instructions in conjunction with the manufacturer’s handbook. Preparation of the instrument is not critical
but take care to prevent rapid temperature fluctuations of the instrument and the conditioning block, for example, avoid them from
direct sunlight or from drafts.
9.2 The results obtained during the use of the equipment are susceptible to error arising from changes in the mag
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