ASTM D7668-12a
(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 and CAN/CGSB3.6. The test method may be applied to the quantitative determination of the derived cetane number of blends of fuel oils containing biodiesel material (for example, Specification D975, biodiesel, 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 2.8 to 6.5 ms and combustion delay ranging from 5.5 to 120 ms (30.0 to 65.0 DCN). However, the precision stated only covers the range of DCN from 35 to 60.
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 and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: D7668 − 12a
StandardTest 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.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 2. Referenced Documents
2
1.1 This test method covers the quantitative determination 2.1 ASTM Standards:
of the derived cetane number of conventional diesel fuel oils, D613Test Method for Cetane Number of Diesel Fuel Oil
diesel fuel oils containing cetane number improver additives, D975Specification for Diesel Fuel Oils
and is applicable to products typical of Specification D975, D1193Specification for Reagent Water
Grades No.1-D and 2-D regular, low and ultra-low-sulfur D4057Practice for Manual Sampling of Petroleum and
diesel fuel oils, European standard EN590, and Canadian Petroleum Products
standards CAN/CGSB-3.517 and CAN/CGSB3.6. The test D4175 Terminology Relating to Petroleum, Petroleum
methodmaybeappliedtothequantitativedeterminationofthe Products, and Lubricants
derived cetane number of blends of fuel oils containing D4177Practice for Automatic Sampling of Petroleum and
biodiesel material (for example, Specification D975, biodiesel, Petroleum Products
and diesel fuel oil blending components. D5854Practice for Mixing and Handling of Liquid Samples
of Petroleum and Petroleum Products
1.2 This test method utilizes a constant volume combustion
D6299Practice for Applying Statistical Quality Assurance
chamber with direct fuel injection into heated, compressed
and Control Charting Techniques to Evaluate Analytical
synthetic air. A dynamic pressure wave is produced from the
Measurement System Performance
combustion of the sample. An equation converts the ignition
D6300Practice for Determination of Precision and Bias
delay and the combustion delay determined from the dynamic
Data for Use in Test Methods for Petroleum Products and
pressure curve to a derived cetane number (DCN).
Lubricants
1.3 This test method covers the ignition delay ranging from
D6708Practice for StatisticalAssessment and Improvement
2.8to6.5msandcombustiondelayrangingfrom5.5to120ms
of Expected Agreement Between Two Test Methods that
(30.0 to 65.0 DCN). However, the precision stated only covers
Purport to Measure the Same Property of a Material
the range of DCN from 35 to 60.
E456Terminology Relating to Quality and Statistics
3
1.4 The values stated in SI units are to be regarded as
2.2 EN Standards:
standard. No other units of measurement are included in this
EN590Automotive Fuels—Diesel—Requirements and Test
standard.
Methods
4
1.5 This standard does not purport to address all of the 2.3 Energy Institute Standards:
safety concerns, if any, associated with its use. It is the IP41Ignition Quality of Diesel Fuels—Cetane Engine Test
responsibility of the user of this standard to establish appro- Method
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
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
1
This test method is under the jurisdiction of ASTM Committee D02 on Standards volume information, refer to the standard’s Document Summary page on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of the ASTM website.
3
Subcommittee D02.01.0C on Test Equipment, Procedures, and Instrumentation. Available from European Committee for Standardization. Central Secretariat:
Current edition approved Nov. 1, 2012. Published November 2013. Originally rue de Stassart, 36,B-1050 Brussels, Belgium.
4
approved in 2010. Last previous edition approved in 2012 as D7668–12. DOI: Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,
10.1520/D7668-12A. U.K., http://www.energyinst.org.uk.
*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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D7668 − 12a
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2.4 Canadian Standards: ignition delay accepted reference value and an assigned com-
CAN/CGSB-3.517 Regular Sulphur Diesel Fuel— bustion delay accepted reference value.
Specification
3.2.2 chamber wall temperature, n—temperature, in °C, of
CAN/CGSB 3.6Automotive Low-Sulphur Diesel Fuel—
the combustion chamber wall.
Specification
3.2.3 charge air, n—compressed synthetic air at a specified
6
2.5 DIN Standards:
p
...
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 − 12 D7668 − 12a
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. The test method may be applied to the quantitative determination of the derived cetane number of blends of
fuel oils containing biodiesel material (for example, Specification D975, biodiesel, 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 2.8 to 6.5 ms and combustion delay ranging from 5.5 to 120 ms
(30.0 to 65.0 DCN). However, the precision stated only covers the range of DCN from 35 to 60.
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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D613 Test Method for Cetane Number of Diesel Fuel Oil
D975 Specification for Diesel Fuel Oils
D1193 Specification for Reagent Water
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum, Petroleum Products, 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 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
E456 Terminology Relating to Quality and Statistics
3
2.2 EN Standards:
EN590 Automotive Fuels—Diesel—Requirements and Test Methods
1
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.01.0C on Test Equipment, Procedures, and Instrumentation.
Current edition approved Sept. 1, 2012Nov. 1, 2012. Published November 2012November 2013. Originally approved in 2010. Last previous edition approved in 20102012
as D7668D7668 – 12.–10. DOI: 10.1520/D7668–10.10.1520/D7668-12A.
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.
3
Available from European Committee for Standardization. Central Secretariat: 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 Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D7668 − 12a
4
2.3 Energy Institute Standards:
IP41 Ignition Quality of Diesel Fuels—Cetane Engine Test Method
5
2.4 Canadian Standards:
CAN/CGSB-3.517 Regular Sulphur Diesel Fuel—Specification
CAN/CGSB 3.6 Automotive Low-Sulphur Diesel Fuel
...
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