ASTM D7668-23
(Test Method)Standard Test Method for Determination of Derived Cetane Number (DCN) of Diesel Fuel Oils—Ignition Delay and Combustion Delay Using a Constant Volume Combustion Chamber Method
Standard Test Method for Determination of Derived Cetane Number (DCN) of Diesel Fuel Oils—Ignition Delay and Combustion Delay Using a Constant Volume Combustion Chamber Method
SIGNIFICANCE AND USE
5.1 The ID and CD values and the DCN value determined by this test method provides a measure of the ignition characteristics of diesel fuel oil used in compression ignition engines.
5.2 This test can be used by engine manufacturers, petroleum refiners and marketers, and in commerce as a specification aid to relate or match fuels and engines.
5.3 The relationship of diesel fuel oil DCN determinations to the performance of full-scale, variable-speed, variable-load diesel engines is not completely understood.
5.4 This test can be applied to non-conventional diesel fuels.
5.5 This test determines ignition characteristics and requires a sample of approximately 370 mL and a test time of approximately 30 min using a fit-for-use instrument.
SCOPE
1.1 This test method covers the quantitative determination of the derived cetane number of conventional diesel fuel oils, diesel fuel oils containing cetane number improver additives, and is applicable to products typical of Specification D975, Grades No.1-D and 2-D regular, low and ultra-low-sulfur diesel fuel oils, European standard EN590, and Canadian standards CAN/CGSB-3.517, CAN/CGSB-3.520, and CAN/CGSB-3.522. The test method may be applied to the quantitative determination of the derived cetane number of biodiesel, blends of diesel fuel oils containing biodiesel material (for example, Specifications D975, D6751, and D7467), and diesel fuel oil blending components.
1.2 This test method utilizes a constant volume combustion chamber with direct fuel injection into heated, compressed synthetic air. A dynamic pressure wave is produced from the combustion of the sample. An equation converts the ignition delay and the combustion delay determined from the dynamic pressure curve to a derived cetane number (DCN).
1.3 This test method covers the ignition delay ranging from 1.9 ms to 25 ms and combustion delay ranging from 2.5 ms to 160 ms (30 DCN to 70 DCN). However, the precision stated only covers the range of DCN results from 38.45 to 64.35.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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.
1.6 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.
General Information
Relations
Buy Standard
Standards Content (Sample)
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.
Designation: D7668 − 23
Standard Test Method for
Determination of Derived Cetane Number (DCN) of Diesel
Fuel Oils—Ignition Delay and Combustion Delay Using a
1
Constant Volume Combustion Chamber Method
This standard is issued under the fixed designation D7668; 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* ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This test method covers the quantitative determination
mendations issued by the World Trade Organization Technical
of the derived cetane number of conventional diesel fuel oils,
Barriers to Trade (TBT) Committee.
diesel fuel oils containing cetane number improver additives,
and is applicable to products typical of Specification D975,
2. Referenced Documents
Grades No.1-D and 2-D regular, low and ultra-low-sulfur
2
2.1 ASTM Standards:
diesel fuel oils, European standard EN590, and Canadian
D613 Test Method for Cetane Number of Diesel Fuel Oil
standards CAN/CGSB-3.517, CAN/CGSB-3.520, and CAN/
D975 Specification for Diesel Fuel
CGSB-3.522. The test method may be applied to the quantita-
D1193 Specification for Reagent Water
tive determination of the derived cetane number of biodiesel,
D4057 Practice for Manual Sampling of Petroleum and
blends of diesel fuel oils containing biodiesel material (for
Petroleum Products
example, Specifications D975, D6751, and D7467), and diesel
D4175 Terminology Relating to Petroleum Products, Liquid
fuel oil blending components.
Fuels, and Lubricants
1.2 This test method utilizes a constant volume combustion
D4177 Practice for Automatic Sampling of Petroleum and
chamber with direct fuel injection into heated, compressed
Petroleum Products
synthetic air. A dynamic pressure wave is produced from the
D5854 Practice for Mixing and Handling of Liquid Samples
combustion of the sample. An equation converts the ignition
of Petroleum and Petroleum Products
delay and the combustion delay determined from the dynamic
D6299 Practice for Applying Statistical Quality Assurance
pressure curve to a derived cetane number (DCN).
and Control Charting Techniques to Evaluate Analytical
1.3 This test method covers the ignition delay ranging from Measurement System Performance
1.9 ms to 25 ms and combustion delay ranging from 2.5 ms to
D6300 Practice for Determination of Precision and Bias
160 ms (30 DCN to 70 DCN). However, the precision stated Data for Use in Test Methods for Petroleum Products,
only covers the range of DCN results from 38.45 to 64.35.
Liquid Fuels, and Lubricants
D6708 Practice for Statistical Assessment and Improvement
1.4 The values stated in SI units are to be regarded as
of Expected Agreement Between Two Test Methods that
standard. No other units of measurement are included in this
Purport to Measure the Same Property of a Material
standard.
D6751 Specification for Biodiesel Fuel Blendstock (B100)
1.5 This standard does not purport to address all of the
for Middle Distillate Fuels
safety concerns, if any, associated with its use. It is the
D7467 Specification for Diesel Fuel Oil, Biodiesel Blend
responsibility of the user of this standard to establish appro-
(B6 to B20)
priate safety, health, and environmental practices and deter-
E456 Terminology Relating to Quality and Statistics
mine the applicability of regulatory limitations prior to use.
3
2.2 EN Standards:
1.6 This international standard was developed in accor-
EN590 Automotive Fuels—Diesel—Requirements and Test
dance with internationally recognized principles on standard-
Methods
1 2
This test method is under the jurisdiction of ASTM Committee D02 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee D02.01 on Combustion Characteristics. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Oct. 1, 2023. Published December 2023. Originally the ASTM website.
3
approved in 2010. Last previous edition approved in 2017 as D7668 – 17. DOI: Available from European Committee for Standardization. Central Secretariat:
10.1520/D7668-23. rue de Stassart, 36,B-1050 Brussels, Belgium.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM 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.
Designation: D7668 − 17 D7668 − 23
Standard Test Method for
Determination of Derived Cetane Number (DCN) of Diesel
Fuel Oils—Ignition Delay and Combustion Delay Using a
1
Constant Volume Combustion Chamber Method
This standard is issued under the fixed designation D7668; 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 the quantitative determination of the derived cetane number of conventional diesel fuel oils, diesel
fuel oils containing cetane number improver additives, and is applicable to products typical of Specification D975, Grades No.1-D
and 2-D regular, low and ultra-low-sulfur diesel fuel oils, European standard EN590, and Canadian standards CAN/CGSB-3.517
and CAN/CGSB3.6.CAN/CGSB-3.517, CAN/CGSB-3.520, and CAN/CGSB-3.522. The test method may be applied to the
quantitative determination of the derived cetane number of biodiesel, blends of diesel fuel oils containing biodiesel material (for
example, Specifications D975, D6751, and D7467), and diesel fuel oil blending components.
1.2 This test method utilizes a constant volume combustion chamber with direct fuel injection into heated, compressed synthetic
air. A dynamic pressure wave is produced from the combustion of the sample. An equation converts the ignition delay and the
combustion delay determined from the dynamic pressure curve to a derived cetane number (DCN).
1.3 This test method covers the ignition delay ranging from 1.9 ms to 25 ms and combustion delay ranging from 2.5 ms to 160 ms
(30 DCN to 70 DCN). However, the precision stated only covers the range of DCN results from 39 to 67.38.45 to 64.35.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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.
1.6 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
2.1 ASTM Standards:
D613 Test Method for Cetane Number of Diesel Fuel Oil
D975 Specification for Diesel Fuel
1
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
D02.01 on Combustion Characteristics.
Current edition approved Oct. 1, 2017Oct. 1, 2023. Published October 2017December 2023. Originally approved in 2010. Last previous edition approved in 20142017
as D7668 – 14a.D7668 – 17. DOI: 10.1520/D7668-17.10.1520/D7668-23.
2
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.
*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
1
---------------------- Page: 1 ----------------------
D7668 − 23
D1193 Specification for Reagent Water
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
D5854 Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products
D6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-
ment System Performance
D6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and
Lubricants
D6708 Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purport
to Measure the Same Property of a Material
D6751 Specification for Biodiesel Fuel Blendstock (B100) for
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.