ASTM D4175-23a

Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants

SCOPE
1.1 This terminology standard covers the compilation of terminology developed by Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants, except that it does not include terms/definitions specific only to the standards in which they appear.  
1.1.1 The terminology, mostly definitions, is unique to petroleum, petroleum products, lubricants, and certain products from biomass and chemical synthesis. Meanings of the same terms outside of applications to petroleum, petroleum products, and lubricants can be found in other compilations and in dictionaries of general usage.  
1.1.2 The terms/definitions exist in two places:  (1) in the standards in which they appear and (2) in this compilation.  
1.2 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

• Status: Published
• Publication Date: 14-Dec-2023
• ICS: 01.040.75 - Petroleum and related technologies (Vocabularies)
• ICS: 75.080 - Petroleum products in general
• ICS: 75.100 - Lubricants, industrial oils and related products
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.95 - Terminology

Relations

• Replaces: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Referred By: ASTM D4865-23 - Standard Guide for Generation and Dissipation of Static Electricity in Petroleum Fuel Systems
• Effective Date: 15-Dec-2023
• Referred By: ASTM D8076-21b - Standard Specification for 100 Research Octane Number Test Fuel for Automotive Spark-Ignition Engines
• Effective Date: 15-Dec-2023
• Referred By: ASTM D8047-23 - Standard Test Method for Evaluation of Engine Oil Aeration Resistance in a Caterpillar C13 Direct-Injected Turbocharged Automotive Diesel Engine
• Effective Date: 15-Dec-2023
• Referred By: ASTM D3606-22 - Standard Test Method for Determination of Benzene and Toluene in Spark Ignition Fuels by Gas Chromatography
• Effective Date: 15-Dec-2023
• Referred By: ASTM D8235-21 - Standard Specification for Ethyl Tertiary-Butyl Ether (ETBE) for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel
• Effective Date: 15-Dec-2023
• Referred By: ASTM D4150-23a - Standard Terminology Relating to Gaseous Fuels
• Effective Date: 15-Dec-2023
• Referred By: ASTM D4057-22 - Standard Practice for Manual Sampling of Petroleum and Petroleum Products
• Effective Date: 15-Dec-2023
• Referred By: ASTM D3237-22 - Standard Test Method for Lead in Gasoline by Atomic Absorption Spectroscopy
• Effective Date: 15-Dec-2023
• Referred By: ASTM D8323-20 - Standard Guide for Management of In-Service Phosphate Ester-based Fluids for Steam Turbine Electro-Hydraulic Control (EHC) Systems
• Effective Date: 15-Dec-2023
• Referred By: ASTM D7423-23 - Standard Test Method for Determination of Oxygenates in C2, C3, C4, and C5 Hydrocarbon Matrices by Gas Chromatography and Flame Ionization Detection
• Effective Date: 15-Dec-2023
• Referred By: ASTM D6421-20 - Standard Test Method for Evaluating Automotive Spark-Ignition Engine Fuel for Electronic Port Fuel Injector Fouling by Bench Procedure
• Effective Date: 15-Dec-2023
• Referred By: ASTM D7757-22 - Standard Test Method for Silicon in Gasoline and Related Products by Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry
• Effective Date: 15-Dec-2023
• Referred By: ASTM D4814-23a - Standard Specification for Automotive Spark-Ignition Engine Fuel
• Effective Date: 15-Dec-2023
• Referred By: ASTM C714-23 - Standard Guide for Thermal Diffusivity of Carbon and Graphite by Thermal Pulse Method
• Effective Date: 15-Dec-2023

Overview

ASTM D4175-23a: Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants provides a comprehensive collection of terms and definitions that are specific to industries dealing with petroleum, liquid fuels, and lubricants. Developed by ASTM Committee D02, this standard serves as a centralized reference, ensuring that professionals, laboratories, manufacturers, and regulators have a common language for effective communication and documentation in the oil, gas, and lubricants sectors. The terminology encompasses products derived from petroleum, certain products from biomass, and those produced through chemical synthesis.

This terminology standard is recognized internationally and aligns with principles set by the World Trade Organization Technical Barriers to Trade (TBT) Committee, assisting global harmonization and clarity within the petroleum industry.

Key Topics

• Specialized Terminology
  Includes unique, industry-specific terms related to petroleum products, liquid fuels, lubricants, and certain derived products.
• Definitions and Explanations
  Provides clear definitions along with notes, discussions, and references to relevant test methods or standards, helping to eliminate ambiguity in technical documents.
• Attribution of Sources
  Each term is attributed to its original source or subcommittee, ensuring traceability and authority.
• Exclusions
  Terms that are only applicable within the context of specific ASTM standards and do not have broader industry relevance are not included in this compilation.
• International Compliance
  Developed in accordance with internationally recognized standardization principles, supporting cross-border conformity.
• Regular Editorial Updates
  Terms are reviewed and updated to reflect current industry practices and advancements.

Applications

The ASTM D4175-23a standard terminology is utilized extensively across the petroleum industry and allied sectors for:

• Technical Communication
  Ensuring consistent language between professionals, organizations, and international stakeholders.
• Specification Documents
  Used in drafting, interpreting, and enforcing technical specifications, procedures, and test methods.
• Quality Assurance and Compliance
  Assisting regulatory bodies and quality managers in assessing conformance to defined terms.
• Training and Onboarding
  Serving as an essential resource for onboarding new personnel and conducting professional training in petroleum-related operations.
• Research & Development
  Facilitating accurate literature reviews, data reporting, and the dissemination of findings in scientific publications.

By standardizing terminology, ASTM D4175-23a reduces misunderstandings and supports safe, efficient, and technically sound handling of petroleum products and lubricants throughout the supply chain.

Related Standards

Professionals referencing ASTM D4175-23a may also consult related standards for comprehensive coverage:

• ASTM D4057 – Practice for Manual Sampling of Petroleum and Petroleum Products
• ASTM D975 – Specification for Diesel Fuel Oils
• ASTM D6092 – Guide for Computing Structural Properties of Biomass-Based Fuels
• ASTM D664 – Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• ISO 4259 – Petroleum Products - Determination and Application of Precision Data in Relation to Methods of Test

Leveraging these standards in conjunction with ASTM D4175-23a streamlines technical communication and promotes best practices in petroleum product analysis, blending, and compliance.

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Keywords: ASTM D4175, petroleum terminology, liquid fuels, lubricants, ASTM standards, petroleum products, standard definitions, international standardization, oil industry glossary, compliance.

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: D4175 − 23a
Standard Terminology Relating to
Petroleum Products, Liquid Fuels, and Lubricants
This standard is issued under the fixed designation D4175; 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.
DISCUSSION—Also called cutting wear in some instances such as
1. Scope*
machining swarf. [D02.96] D7898
1.1 This terminology standard covers the compilation of
terminology developed by Committee D02 on Petroleum
absorbance, n—logarithm to the base 10 of the ratio of the
Products, Liquid Fuels, and Lubricants, except that it does not
reciprocal of the transmittance. [D02.03] D7740
include terms/definitions specific only to the standards in
absorbance, (A), n—the molecular property of a substance that
which they appear.
determines its ability to take up radiant energy, expressed by:
1.1.1 The terminology, mostly definitions, is unique to
petroleum, petroleum products, lubricants, and certain products
A 5 log ~1 ⁄ T! 5 2log ~T!
10 10
from biomass and chemical synthesis. Meanings of the same
where T is the transmittance.
terms outside of applications to petroleum, petroleum products,
DISCUSSION—Absorbance expresses the excess absorption over that
and lubricants can be found in other compilations and in
of a specified reference or standard. It is implied that compensation has
dictionaries of general usage.
been affected for reflectance losses, solvent absorption losses, and
1.1.2 The terms/definitions exist in two places: (1) in the
refractive effects, if present, and that attenuation by scattering is small
standards in which they appear and (2) in this compilation.
compared with attenuation by absorption. [D02.14] D7996
1.2 This international standard was developed in accor-
absorbance, A, n—the molecular property of a substance that
dance with internationally recognized principles on standard-
determines its ability to take up radiant power, expressed by:
ization established in the Decision on Principles for the
A 5 log 1/T 5 2log T
Development of International Standards, Guides and Recom- ~ !
10 10
mendations issued by the World Trade Organization Technical
where T is the transmittance.
Barriers to Trade (TBT) Committee.
DISCUSSION—Absorbance expresses the excess absorption over that
of a specified reference or standard. It is implied that compensation has
2. Terminology
been affected for reflectance losses, solvent absorption losses, and
refractive effects, if present, and that attenuation by scattering is small
2.1 Alphabetical listing of terms with definitions for each
compared with attenuation by absorption. [D02.04] D2008
term showing attributions as to source and subcommittee
jurisdiction is in bold print following the definition. Those
absorbance (A), n—the logarithm to the base 10 of the
showing no attributes are under the jurisdiction of Subcommit-
reciprocal of the transmittance, (T).
tee CS 95.
A 5 log ~1/T! 5 2log T
10 10
1,3-butadiene—hydrocarbon product containing more than
DISCUSSION—Absorbance is a measure of the capacity of a substance
99 % 1,3-butadiene. [D02.D0] D5274
to absorb light of a specific wavelength. [D02.25] D8470
abrasion, n—wear by displacement of material caused by hard
absorptivity, a, n—the specific property of a substance to
particles or hard protuberances. [D02.96] D7684, D7690
absorb radiant power per unit sample concentration and path
length, expressed by:
abrasive wear, n—wear due to hard particles or hard protu-
berances forced against and moving along a solid surface.
a 5 Af/bc
[D02.B0] D4998; [D02.L0] D5182
where:
A = the absorbance,
This terminology is under the jurisdiction of ASTM Committee D02 on f = the dilution factor,
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
b = sample cell path length, and
Subcommittee D02.95 on Terminology.
c = the quantity of absorbing substance contained in a
Current edition approved Dec. 15, 2023. Published December 2023. Originally
ɛ1 volume of solvent.
approved in 1983. Last previous edition approved in 2023 as D4175 – 23 . DOI:
10.1520/D4175-23A. [D02.04] D2008
*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
D4175 − 23a
absorptivity, n—the absorbance divided by the product of the principles, (2) an assigned or certified value, based on
concentration of the substance and the sample pathlength, a experimental work of some national or international
= A/(bc). The units of b and c shall be specified. [D02.25] organization, or (3) a consensus or certified value, based on
D8321 collaborative experimental work under the auspices of a
scientific or engineering group. [D02.25] D3764
acceptance limit (AL), n—a numerical value that defines the
point between making the property conformance or non- accepted reference value, ARV—a value that serves as an
conformance to a specification decision. agreed upon reference for comparison, and which is derived
DISCUSSION—The AL is not necessarily the specification limit. It is a
as: (1) a theoretical or established value, based on scientific
value that takes into account the specification limit, the test method
principles, (2) an assigned value, based on experimental
precision, and the desired probability of making the conformance to
work of some national or international organization such as
specification decision if the true value (see 3.1.17) of the property is at
the U.S. National Institute of Standards and Technology
the specification limit. [D02.94] D3244
(NIST), or (3) a consensus value, based on collaborative
accepted reference value (ARV), n—value that serves as an experimental work under the auspices of a scientific or
agreed-upon reference for comparison and that is derived as
engineering group. [D02.94] D6792
(1) a theoretical or established value, based on scientific
accommodation cracks, n—(also referred to as Mrozowski-
principles, (2) an assigned value, based on experimental
like cracks) cracks and voids formed between basal planes
work of some national or international organization, such as
and at domain interfaces throughout the graphite microstruc-
the U.S. National Institute of Standards and Technology
ture from thermal contraction of the graphite during
(NIST), or (3) a consensus value, based on collaborative
carbonization/graphitization (sometimes referred to as calci-
experimental work under the auspices of a scientific or
nation cracks), from chemical decomposition of the liquid
engineering group. [D02.04] D6596; [D02.25] D8340;
crystal hydrocarbon precursor in graphite manufacture (also
[D02.94] D8428
referred to as calcination cracks) and following cooling after
DISCUSSION—In the context of this test method, accepted reference
graphitization (manufacture). In irradiated graphite, they
value is understood to apply to the cetane number of specific reference
also comprise cracks arising from anisotropic responses to
materials determined empirically under reproducibility conditions by
the National Exchange Group or another recognized exchange testing irradiation. [D02.F0] D8075
organization. [D02.01] D613
accuracy, n—the closeness of agreement between a test result
DISCUSSION—In the context of this test method, accepted reference
and an accepted reference value. [D02.91] D8164;
value is understood to apply to the ignition delay of specific reference
[D02.07] D8278; [D02.94] D6792
materials determined under reproducibility conditions by collaborative
experimental work. [D02.01] D6890 acid number, n—the quantity of a specified base, expressed in
milligrams of potassium hydroxide per gram of sample,
DISCUSSION—In the context of this test method, accepted reference
required to titrate a sample in a specified solvent to a
value is understood to apply to the Motor octane number of specific
specified endpoint using a specified detection system.
reference materials determined empirically under reproducibility con-
[D02.06] D8045; [D02.09] D943
ditions by the National Exchange Group or another recognized ex-
DISCUSSION—In this test method, the acid number is calculated from
change testing organization. [D02.01] D2700
the number of drops required to produce a change in solution color
DISCUSSION—In the context of this test method, accepted reference
from blue-green to orange, compared to the number of drops required
value is understood to apply to the Research octane number of specific
to produce an identical color change using a reference standard.
reference materials determined empirically under reproducibility con-
Because this is a direct comparison method, the acid number value can
ditions by the National Exchange Group or another recognized ex-
be reported in milligrams of potassium hydroxide per gram of sample.
change testing organization. [D02.01] D2699
[D02.06] D5770
DISCUSSION—In the context of this test method, accepted reference
DISCUSSION—In this test method, the indicator is p-naphtholbenzein
value is understood to apply to the supercharge and octane number
titrated to a green/green-brown end point in a toluene-water-
ratings of specific reference materials determined empirically under
isopropanol solvent. [D02.06] D974
reproducibility conditions by the National Exchange Group or another
recognized exchange testing organization. [D02.01] D909 DISCUSSION—In this test method, the solvent is a toluene-water-
isopropanol mixture and the end point is determined when a green/
DISCUSSION—In the context of this test method, accepted reference
green brown color is obtained using the specified p-naphtholbenzein
value is understood to apply to standard fuel or check fuel average
indicator solution. [D02.06] D3242
research or motor octane numbers determined under reproducibility
conditions by a recognized exchange testing organization having a
DISCUSSION—This test method expresses the quantity of base as
minimum of 16 participants. [D02.01] D2885
milligrams of potassium hydroxide per gram of sample, that is required
to titrate a sample in a mixture of toluene and propan-2-ol to which a
DISCUSSION—In the context of this method, accepted reference value
small amount of water has been added from its initial meter reading in
is understood to apply to the ignition delay and the combustion delay
millivolts to a meter reading in millivolts corresponding to an aqueous
of specific reference materials determined under reproducibility condi-
basic buffer solution or a well-defined inflection point as specified in
tions by collaborative experimental work. [D02.01] D7668
the test method. [D02.06] D664
accepted reference value (ARV), n—a value that serves as an
DISCUSSION—This test method provides additional information. The
agreed-upon reference for comparison, and which is derived
quantity of base, expressed as milligrams of potassium hydroxide per
as: (1) a theoretical or established value, based on scientific gram of sample, required to titrate a sample in the solvent from its
D4175 − 23a
initial meter reading in millivolts to a meter reading in millivolts
active sampling, v—to use a sampling device to actively
corresponding to a freshly prepared aqueous acidic buffer solution or a
gather an in-service lubricating grease sample from a grease-
well-defined inflection point as specified in the test method shall be
lubricated component. [D02.G0] D7718
reported as the strong acid number. [D02.06] D664
actuate, v—to hold the interior cylinder of the active grease-
DISCUSSION—The causes and effects of the so-called strong acids and
sampling device while pushing the exterior cylinder forward
the causes and effects of the other acids can be very significantly
toward the grease-lubricated component that is being
different. Therefore, the user of this test method shall differentiate and
sampled allowing lubricating grease to fill the sampling
report the two, when they are found. [D02.06] D664
device. [D02.G0] D7718
acidity, n—the quality, state, or degree of being acid.
acute ecotoxicity, n—the propensity of a material to produce
DISCUSSION—The amount of acid titrated with a base (NaOH or
adverse behavioral, biochemical, or physiological effects in
KOH) in a sample of ethanol or ethanol blend with gasoline, calculated
non-human organisms or populations in a short period of
as acetic acid in mg/kg (ppm mass). [D02.06] D7795
time, usually not constituting a substantial portion of the life
span of the organism. [D02.N0] D6046; [D02.12] D8324
action limit, n—for multivariate spectroscopic analyzers used
in the analysis of liquid petroleum products and fuels, the
acute ecotoxicity, n—the propensity of a test material to
limiting value from an instrument performance test, beyond
produce adverse behavioral, biochemical, or physiological
which the analyzer is expected to produce potentially invalid
effects in non-human organisms or populations in a short
results. [D02.25] D6122
period, usually not constituting a substantial portion of their
life span. [D02.N0] D8029
action limit, n—for multivariate spectroscopic analyzers used
acute ecotoxicity test, n—a comparative ecotoxicity test in
in the analysis of liquid petroleum products and fuels, the
which a representative subpopulation of organisms is ex-
limiting value from an instrument performance test, beyond
posed to different treat rates of a test material and is observed
which the multivariate spectroscopic analyzer is expected to
for a short period, usually not constituting a substantial
produce potentially invalid results. [D02.25] D8470
portion of their life span. [D02.N0] D8029
activated sludge, n—the precipitated solid matter, consisting
acute toxicity test, n—a comparative test in which a represen-
mainly of bacteria and other aquatic microorganisms, that is
tative subpopulation of organisms is exposed to different
produced at a domestic wastewater treatment plant and is
treat rates of a test material and is observed for a short period
used primarily in secondary sewage treatment to microbially
usually not constituting a substantial portion of their life
oxidize dissolved organic matter in the effluent.
span. [D02.12] D6081
[D02.12] D6731, D6139, D6384
additive, n—a material added to another, usually in a small
activation energy (E ), n—measure of temperature effects on
a
amount, to impart or enhance desirable properties or to
the rate of oxidation in the kinetic, or chemical control,
suppress undesirable properties. [D02.B0] D6681
regime. Activation energy is calculated from the Arrhenius
equation: additive, n—in fuel oils, a substance added to fuel oil at a blend
level not greater than 1 % by volume of the finished fuel.
OR 5 Zexp~2E /RT!
a
DISCUSSION—Additives are generally included in finished fuel oil to
where: enhance performance properties (for example, stability, pour point, and
so forth).
OR = oxidation rate,
-1 -1
R = 8.314 J mole K is the universal gas constant,
DISCUSSION—Additives that contain hydrocarbon oil blended with
T = absolute temperature (in Kelvin), and
other substances may exclude the hydrocarbon oil portion for determi-
Z = pre-exponential factor.
nation of the volume percent of the finished fuel.
The activation energy and pre-exponential factor are calcu-
DISCUSSION—Triglycerides (for example, vegetable oils, animal fats,
lated from linearized form of Arrhenius equation, that is, from
greases, and so forth) have been found to cause fouling of fuel oil
burning equipment, and triglycerides are therefore not allowed as
the slope and intercept of the linear plot of the logarithm of
additives or components of additives. [D02.E0] D396
oxidation rate versus the inverse of absolute temperature (1/T):
log ~OR! 5 log Z 2 E /~2.303 RT!
additive, n—in diesel fuels, a substance added to diesel fuel at
10 10 a
Activation energy is expressed in units of kJ/mol. Pre-
a blend level not greater than 1 % by volume of the finished
exponential factor is expressed in the same units as the oxi-
fuel.
-1 -2
dation rates, namely g h m (for Z calculated from area-
a
DISCUSSION—Additives are generally included in finished diesel fuel
-1 -1
normalized oxidation rates, OR ) or g g h (for Z
a w
to enhance performance properties (for example, cetane number,
calculated from weight-normalized oxidation rates, OR ).
w
lubricity, cold flow, etc.).
[D02.F0] D7542
DISCUSSION—Additives that contain hydrocarbon oil blended with
other substances may exclude the hydrocarbon oil portion for determi-
active grease-sampling device, n—device designed to take an
nation of the volume percent of the additive in the finished fuel.
active sample of a lubricating grease from a bearing, gear, or
drive shaft located in a grease-lubricated component.
DISCUSSION—Triglycerides (for example, vegetable oils, animal fats,
[D02.G0] D7718 greases, and so forth) have been found to cause fouling of fuel oil
D4175 − 23a
burning equipment. Similar fouling is expected in diesel engine
aggressiveness index (A.I.), n—the value computed from the
applications and triglycerides are therefore not allowed as additives or
sum of the pH + log alkalinity + log hardness of water
components of additives. [D02.E0] D975
sample where both alkalinity and hardness are reported as
-1
milligram CaCO L .
additive, n—in liquid fuels, a component used in a finished fuel
DISCUSSION—As A.I. decreases, water becomes more corrosive. At
at 1 % by volume (volume fraction) or less that is included
A.I. ≥ 12, water is noncorrosive. At 10 ≤ A.I. < 12, water is moderately
to enhance performance properties of the fuel or to comply
corrosive. At A.I. < 10, water is strongly corrosive. [D02.C0.01]
with a requirement of the finished fuel.
D8506
DISCUSSION—Dilution of an additive to facilitate handling may be
aggressiveness index (A.I.), n—the value computed from the
needed. The volume of the diluent is not considered part of the dosage
of the additive for the purpose of determining the concentration of the sum of the pH + log alkalinity + log hardness of water
additive. [Coordinating Subcommittee D02.95]
sample where both alkalinity and hardness are reported as
milligrams CaCO L.
additive, n—in aviation turbine fuel, a substance added to a
DISCUSSION—As A.I. decreases, water becomes more corrosive. At
base aviation turbine fuel in relatively small amounts that
A.I. ≥ 12, water is noncorrosive. At 10 ≤ A.I. < 12, water is moderately
either enables that base aviation turbine fuel to meet the
corrosive. At A.I. < 10, water is strongly corrosive. [D02.14] D6469
applicable specification properties or does not alter the
applicable specification properties of that base aviation
air-fuel ratio, n—in internal combustion engines, the mass
turbine fuel beyond allowable limits. [D02.J0] D4054
ratio of air-to-fuel in the mixture being induced into the
combustion chambers.
adenosine monophosphate (AMP), n—molecule formed by
[D02.B0] D6593, D6709, D6837, D7589, D8111, D8114,
the removal of two molecules of phosphate (one pyrophos-
D8226, D8350
phate molecule) from ATP. [D02.14] D7463, D7687
DISCUSSION—In this test method, air-fuel ratio (AFR), is controlled
by the EEC IV engine control module. [D02.B0] D6593
adenosine triphosphate (ATP), n—molecule comprised of a
purine and three phosphate groups, that serves as the primary
alarm, n—means of alerting the operator that a particular
energy transport molecule in all biological cells.
condition exists. [D02.96] D7720
[D02.14] D7463, D7687
aliquot, n—portion of sample being tested that is a represen-
adhesive wear (scuffing), n—wear due to localized bonding
tative portion of the whole. [D02.25] D7808
between contacting solid surfaces leading to material trans-
fer between the two surfaces or loss from either surface.
all-levels sample, n—a sample obtained by lowering the closed
[D02.B0] D8074; [D02.L0] D5182
sampling device to the bottom of the outlet suction level, but
always above free water, then opening the sampler and
adiabaticity, n—the condition in which there is no significant
raising it at a uniform rate such that it is between 70 % and
gain or loss of heat throughout the length of the column.
85 % full when withdrawn from the product. Alternatively,
DISCUSSION—When distilling a mixture of compounds as is the case
all-levels samples may be taken with samplers designed for
of crude petroleum, there will be a normal increase in reflux ratio down
the column. In the case where heat losses occur in the column, the filling as they pass downward through the product.
internal reflux is abnormally greater than the reflux in the head. The
DISCUSSION—If required by the test method, the sampler may be
opposite is true when the column gains heat, as with an overheated
greater than 85 % full when withdrawn but in no case shall it be
mantle. [D02.08] D2892
completely full. In these cases, take special handling precautions to
consider the hazards associated with product thermal expansion.
adjustment, n—operation of bringing the portable digital
[D02.02] D4057
density meter to a state of performance suitable for its use,
by setting or adjusting the instrument constants.
alloy, n—unique composition of two or more metals that has
[D02.04] D7777
one or more of the metals treated or processed in a special
way to confer enhanced performance characteristics on the
aerobe, n—an organism that requires oxygen to remain meta-
resulting material. [D02.96] D8182
bolically active.
DISCUSSION—Aerobes use oxygen as their terminal electron acceptor
alpha corrections, n—influence correction factors that com-
in their primary energy-generating metabolic pathways. Aerobes re-
pensate for inter-element X-ray matrix effects; alpha correc-
quire oxygen for survival, using aerobic metabolic processes to
tions may be determined by best-fit regression, XRF Funda-
generate energy for growth and survival. [D02.C0.01] D8506;
mental Parameters (FP), or XRF theory (called theoretical
[D02.14] D6469
alphas). [D02.03] D8252
aerobic, adj—(1) taking place in the presence of oxygen; (2)
alternative blendstock, n—in diesel fuels and fuel oils, a
living or active in the presence of oxygen.
non-hydrocarbon oil substance added to diesel fuel or fuel
[D02.12] D5864, D6006, D6139, D6731;
oil at blend levels greater than 1 % by volume of the finished
[D02.N0] D6046; [D02.14] D8070
fuel.
agglomerate, n—in manufactured carbon and graphite prod-
DISCUSSION—An alternative blendstock should normally have an
uct technology, composite particle containing a number of
industry consensus standard or an annex in this specification that
grains. [D02.F0] D8075 defines its physical and chemical properties.
D4175 − 23a
DISCUSSION—See Appendix X3 for guidance regarding new materials
pounds which can coelute in the primary column.
for No. 1 and No. 2 grades of fuel oils. [D02.E0] D396
[D02.04] D7920
alternative blendstock, n—in diesel fuels and fuel oils, a
analytical column, n—porous layer open tubular (PLOT)
non-hydrocarbon oil substance added to diesel fuel and fuel column with a stationary phase selective for oxygenates; it is
oil at blend levels greater than 1 % by volume of the finished
used to resolve methanol from 1-propanol to provide accu-
fuel. rate quantitative results. [D02.04] D7059
DISCUSSION—An alternative blendstock should normally have an
analytical detector, n—a device used to quantify the com-
industry consensus standard or an annex in this specification that
pounds of interest after they elute from the analytical
defines its physical and chemical properties.
column. [D02.04] D7920
DISCUSSION—See Appendix for guidance regarding new materials for
analytical measurement system, n—a collection of one or
#1-D and #2-D grades of diesel fuels. [D02.E0] D975
more components or subsystems, such as sample handling
amine number of reference fuels above 100, AN,
and preparation, test equipment, instrumentation, display
n—determined in terms of the weight percent of
devices, data handlers, printouts or output transmitters, that
3-methylphenylamine in reference grade isooctane (2,2,4-
are used to determine a quantitative value of a specific
trimethylpentane). For example, 5 % of
property for an unknown sample in accordance with a
3-methylphenylamine in reference grade isooctane has an
standard test method. [D02.94] D7372
amine number of 105 (AN 105). No attempt has been made
analytical measurement system, n—a collection of one or
to correlate performance number of leaded reference fuels to
more components or subsystems, such as samplers, test
the amine number of unleaded reference fuels, and none is
equipment, instrumentation, display devices, data handlers,
implied. [D02.J0] D6424, D6812
and printouts or output transmitters, that is used to determine
amplicon, n—the product of the qPCR reaction resulting from
a quantitative value of a specific property for an unknown
the amplification of a genetic target using a particular pair of
sample in accordance with a test method.
primers. [D02.14] D8412
[Subcommittee D02.94]
DISCUSSION—ASTM or ISO standard test methods are examples of a
ampule, n—a glass vessel for the storage of liquid materials,
test method.
possessing a long narrow neck for the purpose of providing
DISCUSSION—In the context of this test method, the analytical
a flame-sealed closure. [D02.04] D6596
measurement system is comprised of the knock testing unit, automated
analyzer system, and any auxiliary equipment required for the safe
anaerobe, n—an organism that cannot grow or proliferate in
operation of the engine. [D02.01] D2885
the presence of oxygen.
DISCUSSION—Anaerobes use molecules other than oxygen in their
analyzer, n—see analyzer system. [D02.25] D3764, D6122,
primary energy-generating metabolic pathways, such as sulfate, nitrate,
D7808, D8321, D8340
ketones, and other high-energy organic molecules. Although anaerobes
may survive in the presence of oxygen, anaerobic growth typically
analyzer system, n—for equipment in the analysis of liquid
occurs only in an oxygen depleted environment. [D02.C0.01]
petroleum products and fuels, all piping, hardware,
D8506; [D02.14] D6469
computer, software, instrument, linear correlation or multi-
variate model required to analyze a process or product
anaerobic, adj—(1) taking place in the absence of oxygen; (2)
sample; the analyzer system may also be referred to as the
living or active in the absence of oxygen.
analyzer, or the total analyzer system.
[D02.12] D6006; [D02.N0] D6046
DISCUSSION—Online analyzers that utilize extractive sampling in-
clude sample loop, sample conditioning system and excess sample
analysis, n—in multivariate spectroscopic measurement, the
return system.
process of applying the multivariate model to a spectrum,
preprocessed as required, to predict a component concentra-
DISCUSSION—At-line, field and laboratory analyzers include the
tion value or property, the prediction being referred to herein instrument and all associated sample introduction apparatuses.
as a Predicted Primary Test Method Result (PPTMR).
[D02.25] D8340
[D02.25] D8321, D8340
analyzer system, n—for equipment in the analysis of liquid
petroleum products and fuels, all piping, hardware,
analysis cycle time, n—the period of time required to properly
obtain and analyze a representative sample of the process computer, software, instrument, linear correlation or multi-
variate model required to analyze a process or product
stream material. [D02.25] D6624
sample; the analyzer may also be referred to as the analyzer
analysis sample, n—the reduced and divided representative
system, or the total analyzer system.
portion of the bulk sample, prepared for use in the
DISCUSSION—Online analyzers that utilize extractive sampling in-
laboratory. [D02.05] D4930, D6969
clude sample loop, sample conditioning system and excess sample
return system (see Fig. 1 in D3764 for example). Online analyzers that
analyte, n—a specific compound to be measured quantitatively
utilize insertion probes include fiber optics and sample probes.
in a mixture of compounds. [D02.04] D7920
DISCUSSION—At-line, field and laboratory analyzers include the
analytical column, n—a chromatographic column used to instrument and all associated sample introduction apparatuses.
further separate a specific analyte from a mixture of com- [D02.25] D3764
D4175 − 23a
analyzer system, n—for equipment in the analysis of liquid antigen, n—a substance that stimulates the host to produce an
petroleum products and fuels, all piping, hardware, immune response. In the context of this test method, specific
computer, software, instrument, linear correlation or multi- antigens are detected as indicators of microbial
variate model required to analyze a process or product contamination. [D02.14] D8070
sample; the analyzer system may also be referred to as the
antiknock index, n—the arithmetic average of the Research
analyzer, or the total analyzer system.
octane number (RON) and Motor octane number (MON),
DISCUSSION—Online analyzers that utilize extractive sampling in-
that is, (RON + MON) ⁄2. [D02.A0] D4814
clude sample loop, sample conditioning system and excess sample
return system (see Fig. 1 in D3764 for example). Online analyzers that
antimicrobial, n—see biocide. [D02.C0.01] D8506; [D02.14]
utilize insertion probes include fiber optics and sample probes.
D6469
antinodes, n—two or more locations that have local maximum
DISCUSSION—At-line, field and laboratory analyzers include the
instrument and all associated sample introduction apparatuses. displacements, called antinodes, in an unconstrained slender
[D02.25] D6122, D7808, D8321
rod or bar in resonance. For the fundamental flexure
resonance, the antinodes are located at the two ends and the
analyzer unit response time, n—time interval between the
center of the specimen. [D02.F0] C747
introduction of a step change in property characteristic at the
inlet of the analyzer unit and when the analyzer output API gravity, n—a special function of relative density 60/60 °F
(15.56/15.56 °C), represented by:
indicates a value corresponding to 99.5 % of the subsequent
change in analyzer results. [D02.25] D7453
°API 5 @141.5 ⁄ ~r e l a t i v e d e n s i t y 60 ⁄ 60 ° F!#
2 131.5
DISCUSSION—For continuous and intermittent analyzers with suffi-
ciently short cycle times, the total analyzer response time is the [D02.02] D287
analyzer dead time plus 5.3 times the analyzer unit time constant. For
API gravity, n—special function of relative density (specific
intermittent analyzers with long cycle times, the analyzer unit response
gravity) SG60 °F ⁄60 °F, represented by:
time is effectively equal to the analyzer unit cycle time. For intermittent
analyzers with intermediate cycle times, the analyzer unit response time
°API=141.5/~SG60 ° F/60 ° F! 2 131.5
should be defined as the multiple of the analyzer unit cycle time needed
DISCUSSION—Relative density SG15 °C ⁄15 °C is also applied.
to exceed 99.5 % response.
[D02.04] D7777
[D02.25] D3764
apparent density, n—the weight per unit volume of a
Anderson-Darling Resolution Sensitive Statistic, ADrs,
substance, including voids inherent in the material tested.
n—a goodness-of-fit statistical tool used to objectively test
[D02.05] D5502
for normality of proficiency testing data.
DISCUSSION—ADrs is a modified version of the Anderson-Darling
apparent viscosity, n—the determined viscosity obtained by
Statistic (see D6299) and was developed specifically for use in
use of this test method.
assessing normality in proficiency test program data. The ADrs statistic
[D02.07] D3829, D4684, D5133, D6821, D6896
assesses normality regardless of the adequacy of data measurement
DISCUSSION—Apparent viscosity may vary with the spindle speed
resolution relative to the overall variation in the dataset.
(shear rate) of a rotational viscometer if the fluid is non-Newtonian. See
[D02.94] D7372
Appendix X1 for a brief explanation. [D02.07] D2983
aniline point, n—the minimum equilibrium solution tempera-
DISCUSSION—In all cases the term “viscosity” implies that the value
ture for equal volumes of aniline and sample. [D02.04] D611
is the “apparent viscosity.” [D02.07] D8210
DISCUSSION—Apparent viscosity may vary with the spindle speed
annulus—a cut gasket shape consisting of two concentric
(shear rate) of a rotational viscometer when the fluid is non-Newtonian.
circles of known geometry. [D02.B0] F118
[D02.07] D8210
anoxic, adj—oxygen free. [D02.C0.01] D8506; [D02.14]
apparent viscosity, n—of a lubricating grease is the ratio of
D6469
shear stress to shear rate calculated from Poiseuille’s
anti-Stokes line (band), n—a Raman line (band) that has a
equation, and is measured in poises. [D02.G0] D1092
frequency higher than that of the incident monochromatic
apparent viscosity, n—the viscosity determined by this test
beam. [D02.25] D8321
method and expressed in milliPascal seconds. Its value may
antibody, n—an immunoglobulin, a protein that is produced as vary with the spindle and rotational speed selected because
many hot melts are non-Newtonian. [D02.10] D3236
a part of the immune response which is capable of specifi-
cally combining with the antigen.
apparent viscosity, n—the viscosity obtained by use of this
DISCUSSION—In the context of this test method, antibodies created for
test method. [D02.07] D7110
this purpose are utilized in conjunction with visual indicators to detect
presence of microbial antigens. [D02.14] D8070
apparent viscosity, n—viscosity of a non-Newtonian liquid
determined by this test method at a particular shear rate and
antifreeze, n—antifreeze is typically a dilution of ethylene
shear stress. [D02.07] D4683, D4741, D5481
glycol and possibly other glycols, and additives, in water to
act as a machine coolant. 1,2-propanediol is found in some area slice, n—area under a chromatogram within a specified
antifreeze formulations. [D02.04] D7922 retention time interval. [D02.04] D7096
D4175 − 23a
area slice, n—in gas chromatography, the area, resulting from asphaltenes, n—(rarely used in the singular)—in petroleum
the integration of the chromatographic detector signal, technology, represent an oil fraction that is soluble in a
within a specified retention time interval. [D02.04] D7798 specified aromatic solvent but separates upon addition of an
excess of a specified paraffinic solvent.
area-normalized oxidation rate (OR ), n—rate of weight loss
a
DISCUSSION—In this test method, the aromatic solvent is hot toluene
due to oxidation of a machined test specimen at a given
and the paraffinic solvent is heptane.
temperature, divided by the nominal geometric surface area
DISCUSSION—Historically, benzene was the aromatic solvent, but
of the specimen.
benzene is not typically used now for health reasons. The precision of
DISCUSSION—The rate of weight loss is determined by a linear fit of
this test method when using toluene has been found to be the same as
the weight loss plotted against time in the range from 5 % to 10 % loss
when using benzene. [D02.14] D6560
of original specimen weight. The units of area-normalized oxidation
-1 -2
rate, OR , are g h m . [D02.F0] D7542
a
DISCUSSION—In this test method, the aromatic solvent is toluene and
the paraffinic solvent is heptane. [D02.14] D7061, D7827, D7996
area-normalized standard oxidation rate (SOR ), n—value
a
of area normalized oxidation rate corresponding to 1 %
DISCUSSION—In this test method, the aromatic solvent is toluene and
weight loss in 24 h. Area-normalized standard oxidation rate,
the paraffinic solvent is n-heptane. [D02.14] D7157
SOR , depends on the initial specimen density. For carbon
a
-3 DISCUSSION—In this test method, the aromatic solvent is xylene and
and graphite samples (density 1.2 – 2.2 g cm ) SOR varies
a
-1 -2 the paraffinic solvent is n-heptane. [D02.14] D7112
between 2 and 4 g h m . [D02.F0] D7542
DISCUSSION—In this test method, the aromatic solvent is
aromatics, n—in high performance liquid chromatography,
1-methylnapthalene, and the paraffinic solvent is n-hexadecane.
aromatic hydrocarbon components, minus polar material,
[D02.14] D7060
that has a longer retention time than saturates on the
specified polar columns, but can be removed as a single peak
DISCUSSION—Asphaltenes are found largely in crude oils and in
heavy fuel oils containing residual fractions. They are insoluble in
by backflushing the columns with heptane.
alkanes such as heptane and pentane, but soluble in aromatic solvents
DISCUSSION—Generally, aromatic hydrocarbons contain 1 to 4 rings.
such as benzene or toluene. [D02.14] D8253
[D02.04] D7419
assay, n—the procedure to determine the presence, absence, or
aromatics fraction, n—portion of the sample desorbed with
quantity of one or more components. [D02.02] D4057
the polar eluants. The aromatics fraction is divided into
nonpolar and polar based. They may contain aromatics,
assignable cause, n—factor that contributes to variation in a
condensed naphthenic-aromatics, aromatic olefins, and com-
process or product output that is feasible to detect and
pounds containing sulfur, nitrogen, and oxygen atoms.
identify; also called special cause. [D02.96] D7720
[D02.12] D7373
assigned test value (ATV), n—the average of all results
as-calcined particles, n—of coke, those particles that have not
obtained in the several laboratories which are considered
been subject to laboratory crushing. [D02.05] D7454
acceptable based on the reproducibility of the test method.
[D02.94] D3244
aseptic, adj—sterile, free from viable microbiological
contamination. [D02.14] D6974, D7463, D7464, D7687
ASTM color, n—the name of an empirical scale of expressing
the color of a petroleum liquid darker than Saybolt color
ash, n—in carbon and graphite technology, residue remaining
based on a scale of 0.5 (lightest) to 8 Dil (darkest) and
after oxidation of a carbon or graphite. [D02.F0] C561
determined by Test Method D1500. [D02.05] D6045, D6756
asphalt, n—a dark brown-to-black cementitious material in
attenuated total reflection (ATR), n—reflection that occurs
which the predominating constituents are bitumens.
when an absorbing coupling mechanism acts in the process
DISCUSSION—Asphalt can be a natural product or a material obtained
of total internal reflection to make the reflectance less than
from petroleum processing. [D02.G0] D128
unity.
asphalt, n—in North American usage, (1) the heavy, black, DISCUSSION—In this process, if an absorbing sample is placed in
contact with the reflecting surface, the reflectance for total internal
viscous hydrocarbon-based material used for roofing and
reflection will be attenuated to some value between zero and unity (O
paving or (2) mixtures of that material with aggregate or (3)
< R < 1) in regions of the spectrum where absorption of the radiant
finished paving.
power can take place. [D02.25] D8321
DISCUSSION—Asphalt free of aggregate is of three types: (1) natural
asphalt, (2) asphalt from the processing of crude oils, and (3) asphalt
atomic absorption spectrometry, n—analytical technique for
that has been modified by blowing with air or other means. Natural
measuring metal content of solutions, based on a combina-
asphalt is obtained from tar pits or tar lakes, such as those in Trinidad.
tion of flame source, hollow cathode lamp, photomultiplier,
In the refinery, asphalt is usually the residual portion of asphaltic crude
and a readout device. [D02.03] D7740
oil obtained as bottoms from vacuum distillation or by propane
deasphalting. Either of these types of asphalt can be air blown for
atomizer, n—usually a flame source used to decompose the
further removal of lighter fractions and for mild oxidation, to modify
the properties of the final product. chemical constituents in a solution to its elemental
[Coordinating Subcommittee D02.95] components. [D02.03] D7740
D4175 − 23a
audit, n—a systematic examination of the laboratory’s quality backflush, v—elution of the HPLC mobile phase in the
management system documentation and related activities by backward or reverse direction from the silica gel column
an internal or external team to determine conformance to the towards the cyano column.
applicable quality management system standard, such as DISCUSSION—In this test method, it is used to elute the total aromatics
described in this practice. [D02.94] D6792 plus polars as one sharp component. [D02.04] D7419
background RLU, n—quantity of relative light units resulting
autoignition, n—the ignition of a material commonly in the air
from running the test method without incorporation of the
as the result of a heat liberation due to the exothermic
sample. [D02.14] D7687
oxidation reaction in the absensce of an external ignition
source, such as a spark or flame. [Subcommittee D02.01];
bacterium (pl. bacteria), n—a single cell microorganism
[D02.N0] D2155
characterized by the absence of defined intracellular mem-
branes that define all higher life forms.
autoignition temperature, n—the minimum temperature at
DISCUSSION—All bacteria are members of the biological diverse
which autoignition occurs under the specified conditions of
kingdoms Prokaryota and Archaebacteriota. Individual taxa within
the test. [D02.N0] D2155
these kingdoms are able to thrive in environments ranging from
sub-zero temperatures, such as in frozen foods and polar ice, to
automatic sample collector, n—device used to repetitively
superheated waters in deep-sea thermal vents, and over the pH range
extract a grab and collect a representative sample of a batch
<2.0 to >13.0. Potential food sources range from single carbon
or process stream. [D02.25] D7453
molecules (carbon dioxide and methane) to complex polymers, includ-
ing plastics. Oxygen requirements range from obligate anaerobes,
automatic sampler, n—a device used to extract a representa-
which die on contact with oxygen, to obligate aerobes, which die if
tive sample from the liquid flowing in a pipe; the automatic
oxygen pressure falls below a species specific threshold.
sampler generally consists of a probe, a sample extractor, an
[D02.C0.01] D8506; [D02.14] D6469
associated controller, a flow measuring device, and a sample
receiver. [D02.02] D4057 base fuel, n—in automotive spark-ignition engine fuels, a
material composed primarily of hydrocarbons that may also
automatic sampling system, n—system consisting of a sample
contain oxygenates, anti-oxidants, corrosion inhibitors,
probe, sample fast cycle loop, sample supply line stream
metal deactivators, and dyes but does not contain deposit
conditioning, an automatic sampler and an associated
control or lead additives.
controller, a flow measuring device, and sample holding,
DISCUSSION—A jurisdiction may set limits on lead content from all
mixing and handling capabilities. [D02.25] D7453
sources. [D02.A0] D5500, D6201
automotive, adj—descriptive of equipment associated with
base number, n—the quantity of a specified acid, expressed in
self-propelled machinery, usually vehicles driven by internal
terms of the equivalent number of milligrams of potassium
combustion engines. [D02.B0] D4485, D6709, D7216,
hydroxide per gram of sample, required to titrate a sample in
D8047, D8111, D8114, D8226, D8350
a specified solvent to a specified endpoint using a specified
detection system. [D02.06] D2896, D8126
automotive wheel bearing grease, n—a lubricating grease
DISCUSSION—In this test method, the indicator is p-naphtholbenzein
specifically formulated to lubricate automotive wheel bear-
titrated to an orange end point in a toluene-water-isopropanol solvent.
ings at relatively high grease temperatures and bearing
[D02.06] D974
speeds. [D02.G0] D4693
DISCUSSION—In this test method, the sample is titrated to a meter
aviation gasoline, n—gasoline possessing specific properties
reading corresponding to aqueous acidic buffer solution or appropriate
suitable for fueling aircraft powered by reciprocating spark
inflection point. [D02.06] D4739
ignition engines.
DISCUSSION—Principal properties include volatility limits, stability, base oil, n—a base stock or a blend of two or more base stocks
detonation-free performance in the engine for which it is intended and
used to produce finished lubricants, usual
...

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.
´1
Designation: D4175 − 23 D4175 − 23a
Standard Terminology Relating to
Petroleum Products, Liquid Fuels, and Lubricants
This standard is issued under the fixed designation D4175; 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.
ε NOTE—Terms were transferred and updated editorially in October 2023.
1. Scope*
1.1 This terminology standard covers the compilation of terminology developed by Committee D02 on Petroleum Products,
Liquid Fuels, and Lubricants, except that it does not include terms/definitions specific only to the standards in which they appear.
1.1.1 The terminology, mostly definitions, is unique to petroleum, petroleum products, lubricants, and certain products from
biomass and chemical synthesis. Meanings of the same terms outside of applications to petroleum, petroleum products, and
lubricants can be found in other compilations and in dictionaries of general usage.
1.1.2 The terms/definitions exist in two places: (1) in the standards in which they appear and (2) in this compilation.
1.2 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. Terminology
2.1 Alphabetical listing of terms with definitions for each term showing attributions as to source and subcommittee jurisdiction
is in bold print following the definition. Those showing no attributes are under the jurisdiction of Subcommittee CS 95.
1,3-butadiene—hydrocarbon product containing more than 99 % 1,3-butadiene. [D02.D0] D5274
abrasion, n—wear by displacement of material caused by hard particles or hard protuberances. [D02.96] D7684, D7690
abrasive wear, n—wear due to hard particles or hard protuberances forced against and moving along a solid surface. [D02.B0]
D4998; [D02.L0] D5182
DISCUSSION—
Also called cutting wear in some instances such as machining swarf. [D02.96] D7898
absorbance, n—logarithm to the base 10 of the ratio of the reciprocal of the transmittance. [D02.03] D7740
This terminology is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.95 on Terminology.
Current edition approved July 1, 2023Dec. 15, 2023. Published July 2023December 2023. Originally approved in 1983. Last previous edition approved in 20222023 as
ɛ1
D4175 – 22aD4175 – 23 . DOI: 10.1520/D4175-23E01.10.1520/D4175-23A.
*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
D4175 − 23a
absorbance, (A), n—the molecular property of a substance that determines its ability to take up radiant energy, expressed by:
A 5 log ~1 ⁄ T! 52log ~T!
10 10
where T is the transmittance.
DISCUSSION—
Absorbance expresses the excess absorption over that of a specified reference or standard. It is implied that compensation has been affected for
reflectance losses, solvent absorption losses, and refractive effects, if present, and that attenuation by scattering is small compared with attenuation by
absorption. [D02.14] D7996
absorbance, A,n—the molecular property of a substance that determines its ability to take up radiant power, expressed by:
A 5 log ~1/T! 52log T
10 10
where T is the transmittance.
DISCUSSION—
Absorbance expresses the excess absorption over that of a specified reference or standard. It is implied that compensation has been affected for
reflectance losses, solvent absorption losses, and refractive effects, if present, and that attenuation by scattering is small compared with attenuation by
absorption. [D02.04] D2008
absorbance (A), n—the logarithm to the base 10 of the reciprocal of the transmittance, (T).
A 5 log ~1/T! 52log T
10 10
DISCUSSION—
Absorbance is a measure of the capacity of a substance to absorb light of a specific wavelength. [D02.25] D8470
absorptivity, a,n—the specific property of a substance to absorb radiant power per unit sample concentration and path length,
expressed by:
a 5 Af/bc
where:
A = the absorbance,
f = the dilution factor,
b = sample cell path length, and
c = the quantity of absorbing substance contained in a volume of solvent.
[D02.04] D2008
absorptivity, n—the absorbance divided by the product of the concentration of the substance and the sample pathlength, a =
A/(bc). The units of b and c shall be specified. [D02.25] D8321
acceptance limit (AL), n—a numerical value that defines the point between making the property conformance or
non-conformance to a specification decision.
DISCUSSION—
The AL is not necessarily the specification limit. It is a value that takes into account the specification limit, the test method precision, and the desired
probability of making the conformance to specification decision if the true value (see 3.1.17) of the property is at the specification limit. [D02.94]
D3244
accepted reference value (ARV), n—value that serves as an agreed-upon reference for comparison and that is derived as (1)
a theoretical or established value, based on scientific principles, (2) an assigned value, based on experimental work of some
national or international organization, such as the U.S. National Institute of Standards and Technology (NIST), or (3) a consensus
value, based on collaborative experimental work under the auspices of a scientific or engineering group. [D02.04] D6596;
[D02.25] D8340; [D02.94] D8428
DISCUSSION—
In the context of this test method, accepted reference value is understood to apply to the cetane number of specific reference materials determined
empirically under reproducibility conditions by the National Exchange Group or another recognized exchange testing organization. [D02.01] D613
D4175 − 23a
DISCUSSION—
In the context of this test method, accepted reference value is understood to apply to the ignition delay of specific reference materials determined under
reproducibility conditions by collaborative experimental work. [D02.01] D6890
DISCUSSION—
In the context of this test method, accepted reference value is understood to apply to the Motor octane number of specific reference materials
determined empirically under reproducibility conditions by the National Exchange Group or another recognized exchange testing organization.
[D02.01] D2700
DISCUSSION—
In the context of this test method, accepted reference value is understood to apply to the Research octane number of specific reference materials
determined empirically under reproducibility conditions by the National Exchange Group or another recognized exchange testing organization.
[D02.01] D2699
DISCUSSION—
In the context of this test method, accepted reference value is understood to apply to the supercharge and octane number ratings of specific reference
materials determined empirically under reproducibility conditions by the National Exchange Group or another recognized exchange testing
organization. [D02.01] D909
DISCUSSION—
In the context of this test method, accepted reference value is understood to apply to standard fuel or check fuel average research or motor octane
numbers determined under reproducibility conditions by a recognized exchange testing organization having a minimum of 16 participants. [D02.01]
D2885
DISCUSSION—
In the context of this method, accepted reference value is understood to apply to the ignition delay and the combustion delay of specific reference
materials determined under reproducibility conditions by collaborative experimental work. [D02.01] D7668
accepted reference value (ARV), n—a value that serves as an agreed-upon reference for comparison, and which is derived as:
(1) a theoretical or established value, based on scientific principles, (2) an assigned or certified value, based on experimental
work of some national or international organization, or (3) a consensus or certified value, based on collaborative experimental
work under the auspices of a scientific or engineering group. [D02.25] D3764
accepted reference value, ARV—a value that serves as an agreed upon reference for comparison, and which is derived as: (1)
a theoretical or established value, based on scientific principles, (2) an assigned value, based on experimental work of some
national or international organization such as the U.S. National Institute of Standards and Technology (NIST), or (3) a consensus
value, based on collaborative experimental work under the auspices of a scientific or engineering group. [D02.94] D6792
accommodation cracks, n—(also referred to as Mrozowski-like cracks) cracks and voids formed between basal planes and at
domain interfaces throughout the graphite microstructure from thermal contraction of the graphite during carbonization/
graphitization (sometimes referred to as calcination cracks), from chemical decomposition of the liquid crystal hydrocarbon
precursor in graphite manufacture (also referred to as calcination cracks) and following cooling after graphitization
(manufacture). In irradiated graphite, they also comprise cracks arising from anisotropic responses to irradiation. [D02.F0]
D8075
accuracy, n—the closeness of agreement between a test result and an accepted reference value. [D02.91] D8164;
[D02.07] D8278; [D02.94] D6792
acid number, n—the quantity of a specified base, expressed in milligrams of potassium hydroxide per gram of sample, required
to titrate a sample in a specified solvent to a specified endpoint using a specified detection system. [D02.06] D8045; [D02.09]
D943
DISCUSSION—
In this test method, the acid number is calculated from the number of drops required to produce a change in solution color from blue-green to orange,
compared to the number of drops required to produce an identical color change using a reference standard. Because this is a direct comparison method,
the acid number value can be reported in milligrams of potassium hydroxide per gram of sample. [D02.06] D5770
DISCUSSION—
In this test method, the indicator is p-naphtholbenzein titrated to a green/green-brown end point in a toluene-water-isopropanol solvent. [D02.06]
D974
D4175 − 23a
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. [D02.06] D3242
DISCUSSION—
This test method expresses the quantity of base as milligrams of potassium hydroxide per gram of sample, that is required to titrate a sample in a
mixture of toluene and propan-2-ol to which a small amount of water has been added from its initial meter reading in millivolts to a meter reading
in millivolts corresponding to an aqueous basic buffer solution or a well-defined inflection point as specified in the test method. [D02.06] D664
DISCUSSION—
This test method provides additional information. The quantity of base, expressed as milligrams of potassium hydroxide per gram of sample, required
to titrate a sample in the solvent from its initial meter reading in millivolts to a meter reading in millivolts corresponding to a freshly prepared aqueous
acidic buffer solution or a well-defined inflection point as specified in the test method shall be reported as the strong acid number. [D02.06] D664
DISCUSSION—
The causes and effects of the so-called strong acids and the causes and effects of the other acids can be very significantly different. Therefore, the user
of this test method shall differentiate and report the two, when they are found. [D02.06] D664
acidity, n—the quality, state, or degree of being acid.
DISCUSSION—
The amount of acid titrated with a base (NaOH or KOH) in a sample of ethanol or ethanol blend with gasoline, calculated as acetic acid in mg/kg (ppm
mass). [D02.06] D7795
action limit, n—for multivariate spectroscopic analyzers used in the analysis of liquid petroleum products and fuels, the limiting
value from an instrument performance test, beyond which the analyzer is expected to produce potentially invalid results.
[D02.25] D6122
action limit, n—for multivariate spectroscopic analyzers used in the analysis of liquid petroleum products and fuels, the limiting
value from an instrument performance test, beyond which the multivariate spectroscopic analyzer is expected to produce
potentially invalid results. [D02.25] D8470
activated sludge, n—the precipitated solid matter, consisting mainly of bacteria and other aquatic microorganisms, that is
produced at a domestic wastewater treatment plant and is used primarily in secondary sewage treatment to microbially oxidize
dissolved organic matter in the effluent.
[D02.12] D6731, D6139, D6384
activation energy (E ), n—measure of temperature effects on the rate of oxidation in the kinetic, or chemical control, regime.
a
Activation energy is calculated from the Arrhenius equation:
OR 5 Zexp~2E /RT!
a
where:
OR = oxidation rate,
-1 -1
R = 8.314 J mole K is the universal gas constant,
T = absolute temperature (in Kelvin), and
Z = pre-exponential factor.
The activation energy and pre-exponential factor are calculated from linearized form of Arrhenius equation, that is, from the
slope and intercept of the linear plot of the logarithm of oxidation rate versus the inverse of absolute temperature (1/T):
log OR 5 log Z 2 E / 2.303 RT
~ ! ~ !
10 10 a
Activation energy is expressed in units of kJ/mol. Pre-exponential factor is expressed in the same units as the oxidation rates,
-1 -2 -1 -1
namely g h m (for Z calculated from area-normalized oxidation rates, OR ) or g g h (for Z calculated from weight-
a a w
normalized oxidation rates, OR ). [D02.F0] D7542
w
active grease-sampling device, n—device designed to take an active sample of a lubricating grease from a bearing, gear, or
drive shaft located in a grease-lubricated component. [D02.G0] D7718
active sampling, v—to use a sampling device to actively gather an in-service lubricating grease sample from a grease-lubricated
component. [D02.G0] D7718
D4175 − 23a
actuate, v—to hold the interior cylinder of the active grease-sampling device while pushing the exterior cylinder forward toward
the grease-lubricated component that is being sampled allowing lubricating grease to fill the sampling device. [D02.G0] D7718
acute ecotoxicity, n—the propensity of a material to produce adverse behavioral, biochemical, or physiological effects in
non-human organisms or populations in a short period of time, usually not constituting a substantial portion of the life span of
the organism. [D02.N0] D6046; [D02.12] D8324
acute ecotoxicity, n—the propensity of a test material to produce adverse behavioral, biochemical, or physiological effects in
non-human organisms or populations in a short period, usually not constituting a substantial portion of their life span. [D02.N0]
D8029
acute ecotoxicity test, n—a comparative ecotoxicity test in which a representative subpopulation of organisms is exposed to
different treat rates of a test material and is observed for a short period, usually not constituting a substantial portion of their
life span. [D02.N0] D8029
acute toxicity test, n—a comparative test in which a representative subpopulation of organisms is exposed to different treat rates
of a test material and is observed for a short period usually not constituting a substantial portion of their life span. [D02.12]
D6081
additive, n—a material added to another, usually in a small amount, to impart or enhance desirable properties or to suppress
undesirable properties. [D02.B0] D6681
additive, n—in fuel oils, a substance added to fuel oil at a blend level not greater than 1 % by volume of the finished fuel.
DISCUSSION—
Additives are generally included in finished fuel oil to enhance performance properties (for example, stability, pour point, and so forth).
DISCUSSION—
Additives that contain hydrocarbon oil blended with other substances may exclude the hydrocarbon oil portion for determination of the volume percent
of the finished fuel.
DISCUSSION—
Triglycerides (for example, vegetable oils, animal fats, greases, and so forth) have been found to cause fouling of fuel oil burning equipment, and
triglycerides are therefore not allowed as additives or components of additives. [D02.E0] D396
additive, n—in diesel fuels, a substance added to diesel fuel at a blend level not greater than 1 % by volume of the finished fuel.
DISCUSSION—
Additives are generally included in finished diesel fuel to enhance performance properties (for example, cetane number, lubricity, cold flow, etc.).
DISCUSSION—
Additives that contain hydrocarbon oil blended with other substances may exclude the hydrocarbon oil portion for determination of the volume percent
of the additive in the finished fuel.
DISCUSSION—
Triglycerides (for example, vegetable oils, animal fats, greases, and so forth) have been found to cause fouling of fuel oil burning equipment. Similar
fouling is expected in diesel engine applications and triglycerides are therefore not allowed as additives or components of additives. [D02.E0] D975
additive, n—in liquid fuels, a component used in a finished fuel at 1 % by volume (volume fraction) or less that is included to
enhance performance properties of the fuel or to comply with a requirement of the finished fuel.
DISCUSSION—
Dilution of an additive to facilitate handling may be needed. The volume of the diluent is not considered part of the dosage of the additive for the
purpose of determining the concentration of the additive. [Coordinating Subcommittee D02.95]
additive, n—in aviation turbine fuel, a substance added to a base aviation turbine fuel in relatively small amounts that either
enables that base aviation turbine fuel to meet the applicable specification properties or does not alter the applicable specification
properties of that base aviation turbine fuel beyond allowable limits. [D02.J0] D4054
D4175 − 23a
adenosine monophosphate (AMP), n—molecule formed by the removal of two molecules of phosphate (one pyrophosphate
molecule) from ATP. [D02.14] D7463, D7687
adenosine triphosphate (ATP), n—molecule comprised of a purine and three phosphate groups, that serves as the primary
energy transport molecule in all biological cells.
[D02.14] D7463, D7687
adhesive wear (scuffing), n—wear due to localized bonding between contacting solid surfaces leading to material transfer
between the two surfaces or loss from either surface. [D02.B0] D8074; [D02.L0] D5182
adiabaticity, n—the condition in which there is no significant gain or loss of heat throughout the length of the column.
DISCUSSION—
When distilling a mixture of compounds as is the case of crude petroleum, there will be a normal increase in reflux ratio down the column. In the case
where heat losses occur in the column, the internal reflux is abnormally greater than the reflux in the head. The opposite is true when the column gains
heat, as with an overheated mantle. [D02.08] D2892
adjustment, n—operation of bringing the portable digital density meter to a state of performance suitable for its use, by setting
or adjusting the instrument constants.
[D02.04] D7777
aerobe, n—an organism that requires oxygen to remain metabolically active.
DISCUSSION—
Aerobes use oxygen as their terminal electron acceptor in their primary energy-generating metabolic pathways. Aerobes require oxygen for survival,
using aerobic metabolic processes to generate energy for growth and survival. [D02.C0.01] D8506; [D02.14] D6469
aerobic, adj—(1) taking place in the presence of oxygen; (2) living or active in the presence of oxygen.
[D02.12] D5864, D6006, D6139, D6731;
[D02.N0] D6046; [D02.14] D8070
agglomerate, n—in manufactured carbon and graphite product technology, composite particle containing a number of grains.
[D02.F0] D8075
aggressiveness index (A.I.), n—the value computed from the sum of the pH + log alkalinity + log hardness of water sample
-1
where both alkalinity and hardness are reported as milligram CaCO L .
DISCUSSION—
As A.I. decreases, water becomes more corrosive. At A.I. ≥ 12, water is noncorrosive. At 10 ≤ A.I. < 12, water is moderately corrosive. At A.I. < 10,
water is strongly corrosive. [D02.C0.01] D8506
aggressiveness index (A.I.), n—the value computed from the sum of the pH + log alkalinity + log hardness of water sample
where both alkalinity and hardness are reported as milligrams CaCO L.
DISCUSSION—
As A.I. decreases, water becomes more corrosive. At A.I. ≥ 12, water is noncorrosive. At 10 ≤ A.I. < 12, water is moderately corrosive. At A.I. < 10,
water is strongly corrosive. [D02.14] D6469
air-fuel ratio, n—in internal combustion engines, the mass ratio of air-to-fuel in the mixture being induced into the combustion
chambers.
[D02.B0] D6593, D6709, D6837, D7589, D8111, D8114, D8226, D8350
DISCUSSION—
In this test method, air-fuel ratio (AFR), is controlled by the EEC IV engine control module. [D02.B0] D6593
alarm, n—means of alerting the operator that a particular condition exists. [D02.96] D7720
D4175 − 23a
aliquot, n—portion of sample being tested that is a representative portion of the whole. [D02.25] D7808
all-levels sample, n—a sample obtained by lowering the closed sampling device to the bottom of the outlet suction level, but
always above free water, then opening the sampler and raising it at a uniform rate such that it is between 70 % and 85 % full
when withdrawn from the product. Alternatively, all-levels samples may be taken with samplers designed for filling as they pass
downward through the product.
DISCUSSION—
If required by the test method, the sampler may be greater than 85 % full when withdrawn but in no case shall it be completely full. In these cases,
take special handling precautions to consider the hazards associated with product thermal expansion. [D02.02] D4057
alloy, n—unique composition of two or more metals that has one or more of the metals treated or processed in a special way
to confer enhanced performance characteristics on the resulting material. [D02.96] D8182
alpha corrections, n—influence correction factors that compensate for inter-element X-ray matrix effects; alpha corrections may
be determined by best-fit regression, XRF Fundamental Parameters (FP), or XRF theory (called theoretical alphas). [D02.03]
D8252
alternative blendstock, n—in diesel fuels and fuel oils, a non-hydrocarbon oil substance added to diesel fuel or fuel oil at blend
levels greater than 1 % by volume of the finished fuel.
DISCUSSION—
An alternative blendstock should normally have an industry consensus standard or an annex in this specification that defines its physical and chemical
properties.
DISCUSSION—
See Appendix X3 for guidance regarding new materials for No. 1 and No. 2 grades of fuel oils. [D02.E0] D396
alternative blendstock, n—in diesel fuels and fuel oils, a non-hydrocarbon oil substance added to diesel fuel and fuel oil at
blend levels greater than 1 % by volume of the finished fuel.
DISCUSSION—
An alternative blendstock should normally have an industry consensus standard or an annex in this specification that defines its physical and chemical
properties.
DISCUSSION—
See Appendix for guidance regarding new materials for #1-D and #2-D grades of diesel fuels. [D02.E0] D975
amine number of reference fuels above 100, AN, n—determined in terms of the weight percent of 3-methylphenylamine in
reference grade isooctane (2,2,4-trimethylpentane). For example, 5 % of 3-methylphenylamine in reference grade isooctane has
an amine number of 105 (AN 105). No attempt has been made to correlate performance number of leaded reference fuels to the
amine number of unleaded reference fuels, and none is implied. [D02.J0] D6424, D6812
amplicon, n—the product of the qPCR reaction resulting from the amplification of a genetic target using a particular pair of
primers. [D02.14] D8412
ampule, n—a glass vessel for the storage of liquid materials, possessing a long narrow neck for the purpose of providing a
flame-sealed closure. [D02.04] D6596
anaerobe, n—an organism that cannot grow or proliferate in the presence of oxygen.
DISCUSSION—
Anaerobes use molecules other than oxygen in their primary energy-generating metabolic pathways, such as sulfate, nitrate, ketones, and other
high-energy organic molecules. Although anaerobes may survive in the presence of oxygen, anaerobic growth typically occurs only in an oxygen
depleted environment. [D02.C0.01] D8506; [D02.14] D6469
anaerobic, adj—(1) taking place in the absence of oxygen; (2) living or active in the absence of oxygen.
[D02.12] D6006; [D02.N0] D6046
D4175 − 23a
analysis, n—in multivariate spectroscopic measurement, the process of applying the multivariate model to a spectrum,
preprocessed as required, to predict a component concentration value or property, the prediction being referred to herein as a
Predicted Primary Test Method Result (PPTMR). [D02.25] D8321, D8340
analysis cycle time, n—the period of time required to properly obtain and analyze a representative sample of the process stream
material. [D02.25] D6624
analysis sample, n—the reduced and divided representative portion of the bulk sample, prepared for use in the laboratory.
[D02.05] D4930, D6969
analyte, n—a specific compound to be measured quantitatively in a mixture of compounds. [D02.04] D7920
analytical column, n—a chromatographic column used to further separate a specific analyte from a mixture of compounds
which can coelute in the primary column.
[D02.04] D7920
analytical column, n—porous layer open tubular (PLOT) column with a stationary phase selective for oxygenates; it is used to
resolve methanol from 1-propanol to provide accurate quantitative results. [D02.04] D7059
analytical detector, n—a device used to quantify the compounds of interest after they elute from the analytical column. [D02.04]
D7920
analytical measurement system, n—a collection of one or more components or subsystems, such as sample handling and
preparation, test equipment, instrumentation, display devices, data handlers, printouts or output transmitters, that are used to
determine a quantitative value of a specific property for an unknown sample in accordance with a standard test method. [D02.94]
D7372
analytical measurement system, n—a collection of one or more components or subsystems, such as samplers, test equipment,
instrumentation, display devices, data handlers, and printouts or output transmitters, that is used to determine a quantitative value
of a specific property for an unknown sample in accordance with a test method.
[Subcommittee D02.94]
DISCUSSION—
ASTM or ISO standard test methods are examples of a test method.
DISCUSSION—
In the context of this test method, the analytical measurement system is comprised of the knock testing unit, automated analyzer system, and any
auxiliary equipment required for the safe operation of the engine. [D02.01] D2885
analyzer, n—see analyzer system. [D02.25] D3764, D6122, D7808, D8321, D8340
analyzer system, n—for equipment in the analysis of liquid petroleum products and fuels, all piping, hardware, computer,
software, instrument, linear correlation or multivariate model required to analyze a process or product sample; the analyzer
system may also be referred to as the analyzer, or the total analyzer system.
DISCUSSION—
Online analyzers that utilize extractive sampling include sample loop, sample conditioning system and excess sample return system.
DISCUSSION—
At-line, field and laboratory analyzers include the instrument and all associated sample introduction apparatuses.
[D02.25] D8340
analyzer system, n—for equipment in the analysis of liquid petroleum products and fuels, all piping, hardware, computer,
software, instrument, linear correlation or multivariate model required to analyze a process or product sample; the analyzer may
also be referred to as the analyzer system, or the total analyzer system.
D4175 − 23a
DISCUSSION—
Online analyzers that utilize extractive sampling include sample loop, sample conditioning system and excess sample return system (see Fig. 1 in
D3764 for example). Online analyzers that utilize insertion probes include fiber optics and sample probes.
DISCUSSION—
At-line, field and laboratory analyzers include the instrument and all associated sample introduction apparatuses.
[D02.25] D3764
analyzer system, n—for equipment in the analysis of liquid petroleum products and fuels, all piping, hardware, computer,
software, instrument, linear correlation or multivariate model required to analyze a process or product sample; the analyzer
system may also be referred to as the analyzer, or the total analyzer system.
DISCUSSION—
Online analyzers that utilize extractive sampling include sample loop, sample conditioning system and excess sample return system (see Fig. 1 in
D3764 for example). Online analyzers that utilize insertion probes include fiber optics and sample probes.
DISCUSSION—
At-line, field and laboratory analyzers include the instrument and all associated sample introduction apparatuses.
[D02.25] D6122, D7808, D8321
analyzer unit response time, n—time interval between the introduction of a step change in property characteristic at the inlet
of the analyzer unit and when the analyzer output indicates a value corresponding to 99.5 % of the subsequent change in analyzer
results. [D02.25] D7453
DISCUSSION—
For continuous and intermittent analyzers with sufficiently short cycle times, the total analyzer response time is the analyzer dead time plus 5.3 times
the analyzer unit time constant. For intermittent analyzers with long cycle times, the analyzer unit response time is effectively equal to the analyzer
unit cycle time. For intermittent analyzers with intermediate cycle times, the analyzer unit response time should be defined as the multiple of the
analyzer unit cycle time needed to exceed 99.5 % response.
[D02.25] D3764
Anderson-Darling Resolution Sensitive Statistic, ADrs, n—a goodness-of-fit statistical tool used to objectively test for
normality of proficiency testing data.
DISCUSSION—
ADrs is a modified version of the Anderson-Darling Statistic (see D6299) and was developed specifically for use in assessing normality in proficiency
test program data. The ADrs statistic assesses normality regardless of the adequacy of data measurement resolution relative to the overall variation in
the dataset.
[D02.94] D7372
aniline point, n—the minimum equilibrium solution temperature for equal volumes of aniline and sample. [D02.04] D611
annulus—a cut gasket shape consisting of two concentric circles of known geometry. [D02.B0] F118
anoxic, adj—oxygen free. [D02.C0.01] D8506; [D02.14] D6469
anti-Stokes line (band), n—a Raman line (band) that has a frequency higher than that of the incident monochromatic beam.
[D02.25] D8321
antibody, n—an immunoglobulin, a protein that is produced as a part of the immune response which is capable of specifically
combining with the antigen.
DISCUSSION—
In the context of this test method, antibodies created for this purpose are utilized in conjunction with visual indicators to detect presence of microbial
antigens. [D02.14] D8070
antifreeze, n—antifreeze is typically a dilution of ethylene glycol and possibly other glycols, and additives, in water to act as
a machine coolant. 1,2-propanediol is found in some antifreeze formulations. [D02.04] D7922
antigen, n—a substance that stimulates the host to produce an immune response. In the context of this test method, specific
antigens are detected as indicators of microbial contamination. [D02.14] D8070
D4175 − 23a
antiknock index, n—the arithmetic average of the Research octane number (RON) and Motor octane number (MON), that is,
(RON + MON) ⁄2. [D02.A0] D4814
antimicrobial, n—see biocide. [D02.C0.01] D8506; [D02.14] D6469
antinodes, n—two or more locations that have local maximum displacements, called antinodes, in an unconstrained slender rod
or bar in resonance. For the fundamental flexure resonance, the antinodes are located at the two ends and the center of the
specimen. [D02.F0] C747
API gravity, n—a special function of relative density 60/60 °F (15.56/15.56 °C), represented by:
°API 5 @141.5 ⁄ ~r e l a t i v e d e n s i t y 60 ⁄ 60 ° F!# 2 131.5
[D02.02] D287
API gravity, n—special function of relative density (specific gravity) SG60 °F ⁄60 °F, represented by:
°API=141.5/ SG60 ° F/60 ° F 2 131.5
~ !
DISCUSSION—
Relative density SG15 °C ⁄15 °C is also applied. [D02.04] D7777
apparent density, n—the weight per unit volume of a substance, including voids inherent in the material tested. [D02.05] D5502
apparent viscosity, n—the determined viscosity obtained by use of this test method.
[D02.07] D3829, D4684, D5133, D6821, D6896
DISCUSSION—
Apparent viscosity may vary with the spindle speed (shear rate) of a rotational viscometer if the fluid is non-Newtonian. See Appendix X1 for a brief
explanation. [D02.07] D2983
DISCUSSION—
In all cases the term “viscosity” implies that the value is the “apparent viscosity.” [D02.07] D8210
DISCUSSION—
Apparent viscosity may vary with the spindle speed (shear rate) of a rotational viscometer when the fluid is non-Newtonian. [D02.07] D8210
apparent viscosity, n—of a lubricating grease is the ratio of shear stress to shear rate calculated from Poiseuille’s equation, and
is measured in poises. [D02.G0] D1092
apparent viscosity, n—the viscosity determined by this test method and expressed in milliPascal seconds. Its value may vary
with the spindle and rotational speed selected because many hot melts are non-Newtonian. [D02.10] D3236
apparent viscosity, n—the viscosity obtained by use of this test method. [D02.07] D7110
apparent viscosity, n—viscosity of a non-Newtonian liquid determined by this test method at a particular shear rate and shear
stress. [D02.07] D4683, D4741, D5481
area slice, n—area under a chromatogram within a specified retention time interval. [D02.04] D7096
area slice, n—in gas chromatography, the area, resulting from the integration of the chromatographic detector signal, within a
specified retention time interval. [D02.04] D7798
area-normalized oxidation rate (OR ), n—rate of weight loss due to oxidation of a machined test specimen at a given
a
temperature, divided by the nominal geometric surface area of the specimen.
D4175 − 23a
DISCUSSION—
The rate of weight loss is determined by a linear fit of the weight loss plotted against time in the range from 5 % to 10 % loss of original specimen
-1 -2
weight. The units of area-normalized oxidation rate, OR , are g h m . [D02.F0] D7542
a
area-normalized standard oxidation rate (SOR ), n—value of area normalized oxidation rate corresponding to 1 % weight
a
loss in 24 h. Area-normalized standard oxidation rate, SOR , depends on the initial specimen density. For carbon and graphite
a
-3 -1 -2
samples (density 1.2 – 2.2 g cm ) SOR varies between 2 and 4 g h m . [D02.F0] D7542
a
aromatics, n—in high performance liquid chromatography, aromatic hydrocarbon components, minus polar material, that has
a longer retention time than saturates on the specified polar columns, but can be removed as a single peak by backflushing the
columns with heptane.
DISCUSSION—
Generally, aromatic hydrocarbons contain 1 to 4 rings. [D02.04] D7419
aromatics fraction, n—portion of the sample desorbed with the polar eluants. The aromatics fraction is divided into nonpolar
and polar based. They may contain aromatics, condensed naphthenic-aromatics, aromatic olefins, and compounds containing
sulfur, nitrogen, and oxygen atoms. [D02.12] D7373
as-calcined particles, n—of coke, those particles that have not been subject to laboratory crushing. [D02.05] D7454
aseptic, adj—sterile, free from viable microbiological contamination. [D02.14] D6974, D7463, D7464, D7687
ash, n—in carbon and graphite technology, residue remaining after oxidation of a carbon or graphite. [D02.F0] C561
asphalt, n—a dark brown-to-black cementitious material in which the predominating constituents are bitumens.
DISCUSSION—
Asphalt can be a natural product or a material obtained from petroleum processing. [D02.G0] D128
asphalt, n—in North American usage, (1) the heavy, black, viscous hydrocarbon-based material used for roofing and paving or
(2) mixtures of that material with aggregate or (3) finished paving.
DISCUSSION—
Asphalt free of aggregate is of three types: (1) natural asphalt, (2) asphalt from the processing of crude oils, and (3) asphalt that has been modified
by blowing with air or other means. Natural asphalt is obtained from tar pits or tar lakes, such as those in Trinidad. In the refinery, asphalt is usually
the residual portion of asphaltic crude oil obtained as bottoms from vacuum distillation or by propane deasphalting. Either of these types of asphalt
can be air blown for further removal of lighter fractions and for mild oxidation, to modify the properties of the final product.
[Coordinating Subcommittee D02.95]
asphaltenes, n—(rarely used in the singular)—in petroleum technology, represent an oil fraction that is soluble in a specified
aromatic solvent but separates upon addition of an excess of a specified paraffinic solvent.
DISCUSSION—
In this test method, the aromatic solvent is hot toluene and the paraffinic solvent is heptane.
DISCUSSION—
Historically, benzene was the aromatic solvent, but benzene is not typically used now for health reasons. The precision of this test method when using
toluene has been found to be the same as when using benzene. [D02.14] D6560
DISCUSSION—
In this test method, the aromatic solvent is toluene and the paraffinic solvent is heptane. [D02.14] D7061, D7827, D7996
DISCUSSION—
In this test method, the aromatic solvent is toluene and the paraffinic solvent is n-heptane. [D02.14] D7157
DISCUSSION—
In this test method, the aromatic solvent is xylene and the paraffinic solvent is n-heptane. [D02.14] D7112
DISCUSSION—
In this test method, the aromatic solvent is 1-methylnapthalene, and the paraffinic solvent is n-hexadecane. [D02.14] D7060
D4175 − 23a
DISCUSSION—
Asphaltenes are found largely in crude oils and in heavy fuel oils containing residual fractions. They are insoluble in alkanes such as heptane and
pentane, but soluble in aromatic solvents such as benzene or toluene. [D02.14] D8253
assay, n—the procedure to determine the presence, absence, or quantity of one or more components. [D02.02] D4057
assignable cause, n—factor that contributes to variation in a process or product output that is feasible to detect and identify; also
called special cause. [D02.96] D7720
assigned test value (ATV), n—the average of all results obtained in the several laboratories which are considered acceptable
based on the reproducibility of the test method. [D02.94] D3244
ASTM color, n—the name of an empirical scale of expressing the color of a petroleum liquid darker than Saybolt color based
on a scale of 0.5 (lightest) to 8 Dil (darkest) and determined by Test Method D1500. [D02.05] D6045, D6756
attenuated total reflection (ATR), n—reflection that occurs when an absorbing coupling mechanism acts in the process of total
internal reflection to make the reflectance less than unity.
DISCUSSION—
In this process, if an absorbing sample is placed in contact with the reflecting surface, the reflectance for total internal reflection will be attenuated
to some value between zero and unity (O < R < 1) in regions of the spectrum where absorption of the radiant power can take place. [D02.25] D8321
atomic absorption spectrometry, n—analytical technique for measuring metal content of solutions, based on a combination of
flame source, hollow cathode lamp, photomultiplier, and a readout device. [D02.03] D7740
atomizer, n—usually a flame source used to decompose the chemical constituents in a solution to its elemental components.
[D02.03] D7740
audit, n—a systematic examination of the laboratory’s quality management system documentation and related activities by an
internal or external team to determine conformance to the applicable quality management system standard, such as described
in this practice. [D02.94] D6792
autoignition, n—the ignition of a material commonly in the air as the result of a heat liberation due to the exothermic oxidation
reaction in the absensce of an external ignition source, such as a spark or flame. [Subcommittee D02.01]; [D02.N0] D2155
autoignition temperature, n—the minimum temperature at which autoignition occurs under the specified conditions of the test.
[D02.N0] D2155
automatic sample collector, n—device used to repetitively extract a grab and collect a representative sample of a batch or
process stream. [D02.25] D7453
automatic sampler, n—a device used to extract a representative sample from the liquid flowing in a pipe; the automatic sampler
generally consists of a probe, a sample extractor, an associated controller, a flow measuring device, and a sample receiver.
[D02.02] D4057
automatic sampling system, n—system consisting of a sample probe, sample fast cycle loop, sample supply line stream
conditioning, an automatic sampler and an associated controller, a flow measuring device, and sample holding, mixing and
handling capabilities. [D02.25] D7453
automotive, adj—descriptive of equipment associated with self-propelled machinery, usually vehicles driven by internal
combustion engines. [D02.B0] D4485, D6709, D7216, D8047, D8111, D8114, D8226, D8350
D4175 − 23a
automotive wheel bearing grease, n—a lubricating grease specifically formulated to lubricate automotive wheel bearings at
relatively high grease temperatures and bearing speeds. [D02.G0] D4693
aviation gasoline, n—gasoline possessing specific properties suitable for fueling aircraft powered by reciprocating spark
ignition engines.
DISCUSSION—
Principal properties include volatility limits, stability, detonation-free performance in the engine for which it is intended and suitability for low
temperature performance.
[D02.J0] D910, D6227
aviation turbine fuel, n—refined petroleum distillate, generally used as a fuel for aviation gas turbines.
DISCUSSION—
Different grades are characterized by volatility ranges, freeze point, and by flash point. [D02.J0] D1322
B6 to B20, n—fuel blend consisting of 6 volume percent to 20 volume percent biodiesel conforming to the requirements of
Specification D6751 with the remainder being a light middle or middle distillate grade diesel fuel and meeting the requirements
of this specification.
DISCUSSION—
The abbreviation BXX represents a specific blend concentration in the range B6 to B20, where XX is the percent volume of biodiesel in the fuel blend.
[D02.E0] D7467
backflush, v—elution of the HPLC mobile phase in the backward or reverse direction from the silica gel column towards the
cyano column.
DISCUSSION—
In this test method, it is used to elute the total aromatics plus polars as one sharp component. [D02.04] D7419
background RLU, n—quantity of relative light units resulting from running the test method without incorporation of the
sample. [D02.14] D7687
bacterium (pl. bacteria), n—a single cell microorganism characterized by the absence of defined intracellular membranes that
define all higher life forms.
DISCUSSION—
All bacteria are members of the biological diverse kingdoms Prokaryota and Archaebacteriota. Individual taxa within these kingdoms are able to thrive
in environments ranging from sub-zero temperatures, such as in frozen foods and polar ice, to superheated waters in deep-sea thermal vents, and over
the pH range <2.0 to >13.0. Potential food sources range from single carbon molecules (carbon
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