ASTM D3242-08

This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
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.
An American National Standard
Designation:D3242–07 Designation:D3242–08
Designation: 354/98
Standard Test Method for
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Acidity in Aviation Turbine Fuel
This standard is issued under the fixed designation D 3242; 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*
1.1 Thistestmethodcoversthedeterminationoftheacidityinaviationturbinefuelintherangefrom0.000to0.100mgKOH/g.
1.2
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.
2. Referenced Documents
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2.1 ASTM Standards:
D 664 Test Method for Acid Number of Petroleum Products by Potentiometric Titration
D 1193 Specification for Reagent Water
3. Terminology
3.1 Definitions:
3.1.1 acid number, n—quantity of base, expressed in milligrams of potassium hydroxide per gram of sample that is required
to titrate a sample in a specific solvent to a specific end point.
3.1.1.1 Discussion—in this test method, the solvent is a toluene-water-isopropanol mixture and the end point is determined
when a green/green brown color is obtained using the specified p-naphtholbenzein indicator solution.
4. Summary of Test Method
4.1 The sample is dissolved in a mixture of toluene and isopropyl alcohol containing a small amount of water. The resulting
single phase solution is blanketed by a stream of nitrogen bubbling through it and is titrated with standard alcoholic potassium
hydroxide to the end point indicated by the color change (orange in acid and green in base) of the added p-naphtholbenzein
solution.
5. Significance and Use
5.1 Someacidscanbepresentinaviationturbinefuelsdueeithertotheacidtreatmentduringtherefiningprocessortonaturally
occurring organic acids. Significant acid contamination is not likely to be present because of the many check tests made during
the various stages of refining. However, trace amounts of acid can be present and are undesirable because of the consequent
tendencies of the fuel to corrode metals that it contacts or to impair the water separation characteristics of the aviation turbine fuel.
5.2 This test method is designed to measure the levels of acidity that can be present in aviation turbine fuel and is not suitable
for determining significant acid contamination.
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This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.06 on
Analysis of Lubricants.
Current edition approved Nov.July 1, 2007.2008. Published November 2007.August 2008. Originally approved in 1973. Last previous edition approved in 20052007 as
D 3242–057.
This test method has been approved by the sponsoring committees and accepted by the cooperating societies in accordance with established procedures.
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For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM 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.
*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.
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D3242–08
6. Apparatus
6.1 Buret—A 25-mL buret graduated in 0.1-mL subdivisions, or a 10-mL buret graduated in 0.05-mL subdivisions.
NOTE 1—An automated buret capable of delivering titrant amounts in 0.05 mL or smaller increments can be used, but the stated precision data were
obtained using manual burets only.
7. Reagents and Materials
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
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such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of suffici
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