ASTM D4175 Terminology Relating to Petroleum, Petroleum Products, and Lubricants
calcined coke, n - petroleum coke that has been thermally treated to drive off the volatile matter and to develop crystalline structure.
calcined petroleum coke, n - petroleum coke that has been thermally treated to drive off the volatile matter and to develop crystalline structure.
calcined petroleum coke, n - raw petroleum coke that has been thermally treated to drive off the volatile matter and to develop crystalline structure.
calibrate, v - to determine the indication or output of a measuring device with respect to that of a standard.
calibrate, v - to determine the indication or output of a measuring device or a given engine with respect to a standard.
calibrated test stand, n - a test stand on which the testing of reference material(s), conducted as specified in the standard, provided acceptable test results.

DISCUSSION - In several automotive lubricant standard test methods, the ASTM Test Monitoring Center provides testing guidance and determines acceptability.

calibration, n - the act of determining the indication or output of a measuring device or a given engine with respect to a standard.
calibration, n - the determination of the values of the significant parameters by comparison with values indicated by a set of reference standards.
calibration curve, n - the graphical or mathematical representation of a relationship between the assigned (known) values of standards and the measured responses from the measurement system.
calibration oil, n - an oil that is used to determine the indication or output of a measuring device or a given engine with respect to a standard.
calibration standard, n - a standard having an accepted value (reference value) for use in calibrating a measurement instrument or system.
calibration standard, n - a material with a certified value for a relevant property, issued by or traceable to a national organization such as NIST, and whose properties are known with sufficient accuracy to permit its use to evaluate the same property of another sample.
calibration standard, n - a standard having an assigned (known) value (reference value) for use in calibrating a measurement instrument or system. This standard is not used to determine the accuracy of the measurement instrument or system (see check standard).
calibration test, n - an engine test conducted on a reference oil under carefully prescribed conditions, the results of which are used to determine the suitability of the engine stand/laboratory for such tests on non-reference oils.

DISCUSSION - A calibration test also includes tests conducted on parts to ensure their suitability for use in reference and non-reference tests.

calibration test, n - a test, using a coded oil, conducted as specified in the test method.

DISCUSSION - The test result is used to determine the suitability of the testing facility/laboratory to conduct such tests on non-reference oils.

calibration test stand, n - a test stand on which the testing of reference material(s), conducted as specified in the standard, provided acceptable results.

DISCUSSION - In several automotive lubricant standard test methods, the ASTM Test Monitoring Center provides testing guidance and determines acceptability.

candidate oil, n - an oil that is intended to have the performance characteristics necessary to satisfy a specification and is to be tested against that specification.

DISCUSSION - These oils are mainly submitted for testing as candidates to satisfy a specified performance; hence the designation of the term.

candle pitch, n - a dark brown-to-black, tarry or solid, byproduct residue from soap and candle stock manufacture, refining of vegetable oils, refining of wool grease, or refining of refuse animal fats.
carbon, n - an element, number 6 of the periodic table of elements, electronic ground state 1s(2)2s(2)2p(2).
carbon, n - in carbon and graphite technology, an artifact consisting predominantly of the element carbon and possessing limited long range order.

DISCUSSION - The presence of limited long range order is usually associated with low electrical and thermal conductivity and difficult machinability when compared with graphite.

carbon, n - in manual transmissions and final drive axles, a hard, dry, generally black or gray deposit that can be removed by solvents but not by wiping with a cloth.
carbon foam, n - in carbon and graphite technology, a porous carbon product containing regularly shaped, predominantly concave, homogeneously dispersed cells which interact to form a three-dimensional array throughout a continuum material of carbon, predominantly in the non-graphitic state. The final result is either an open or closed cell product.

DISCUSSION - In most foam, the cell wall thickness is less than half the average cell size.

carbon residue, n - in petroleum products, the part remaining after a sample has been subjected to thermal decomposition.

DISCUSSION - The amount of residue is dependent on the test conditions of evaporation and pyrolysis. The term may be misleading here in that the residue may contain other than carbon decomposition products. However, the term is retained due to its wide common usage.

carbon residue, n - the residue formed by evaporation and thermal degradation of a carbon containing material.

DISCUSSION - The residue is not composed entirely of carbon but is a coke that can be further changed by carbon pyrolysis. The term carbon residue is retained in deference to its wide common usage.

category, n - in engine oils, a designation such as SH, SJ, SL, SM, CF-4, CF, CF-2, CG-4, CH-4, CI-4, Energy Conserving, and so forth, for a given level of performance in specified engine and bench tests.
CCCFP, n - continually closed cup flash point cell (bubble), n - in carbon and graphite technology, a single small cavity formed by gaseous displacement in a precursor material in its plastic state, and surrounded completely by its walls when formed. Cells can be open or closed.

DISCUSSION - After processing at high temperatures, the basic structure of the cell will remain even as the material converts from a plastic state to a rigid carbonaceous structure. Hence, the term cell will apply to a carbon product.

cell count, n - in carbon and graphite technology, in closed-cell foams, the number of cells aligned in one plane in one linear inch, as determined by stereoscopic image analysis.
cell size, n - in carbon and graphite technology, the average diameter of the cells in the final foam product.
certified reference material, CRM, n - a reference material one or more of whose property values are certified by a technically valid procedure, accompanied by a traceable certificate or other documentation which is issued by a certifying body.
cetane index, n - an approximation of the cetane number (the ignition performance) of distillate diesel fuel, which does not contain a cetane improver additive, calculated from the density and the mid-boiling point temperature (see also diesel index).
cetane number, n - a measure of the ignition performance of a diesel fuel oil obtained by comparing it to reference fuels in a standardized engine test.

DISCUSSION - In the context of this method, ignition performance is understood to mean the ignition delay of the fuel as determined in a standard test engine under controlled conditions of fuel flow rate, injection timing and compression ratio.

DISCUSSION - In the context of this test method, cetane number is that defined by Test Method D613/IP 41.

cetane number (cn), n - a measure of the ignition performance of a diesel fuel obtained by comparing it to reference fuels in a standardized engine test.
CFU, n - colony forming unit
charge volume, n - the volume of the specimen, 100 mL, charged to the distillation flask at the temperature specified in Table 1.
charge volume, n - in petroleum products, in distillation, volume of the liquid sample transferred to the specimen container.
Check Fuel, n - for quality control testing, a spark-ignition engine fuel of selected characteristics having an octane number accepted reference value (O.N.ARV) determined by round-robin testing under reproducibility conditions.
check fuel, n - for quality control testing, a spark-ignition aviation gasoline having supercharge rating ARV determined by the National Exchange Group.
check standard, n - a material having an assigned (known) value (reference value) used to determine the accuracy of the measurement instrument or system. This standard is not used to calibrate the measurement instrument or system (see calibration standard).
check standard, n - in QC testing, material having an accepted reference value used to determine the accuracy of a measurement system.

DISCUSSION - In the context of this test method, check standard refers to heptane.

chronic 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 period of time which constitutes a major portion of their life span.
chronic toxicity test, n - a comparative toxicity test in which a representative subpopulation of organisms are exposed to different treat rates of a test material and is observed for a period of time which constitutes a major portion of their life span.
CHT, n - cylinder head temperature
CIE, n - the abbreviation for the French title of the International Commission on Illumination, or Commission Internationale de l'Eclairage.
CIE Standard Illuminant C, n - Colorimetric illuminant, representing daylight with a correlated color temperature of 6774 K, defined by the CIE in terms of a relative spectral power distribution.
CIE 1931 standard observer, n - ideal colorimetric observer with color matching functions x (λ), y (λ), z (λ) corresponding to a field of view subtending a 2° angle on the retina; commonly called the "2° Standard Observer".
C.L.A., n - in measuring surface finish, the arithmetic average of the absolute distances of all profile points from the mean line for a given distance.
classification, n - in engine oils, the systematic arrangement into categories in accordance with different levels of performance in specified engine and bench tests.
clogging, n - the restriction of a flow path due to the accumulation of material along the flow path boundaries.
closed cell, n - in carbon and graphite technology, a cell totally enclosed by its walls and hence not interconnected with other cells. A closed cell foam is a foam consisting predominantly of closed cells.
closeness sum of squares (CSS), n - a statistic used to quantify the degree of agreement between the results from two test methods after bias-correction using the methodology of this practice.
cloud point, n - in petroleum products and biodiesel fuels, the temperature of a liquid specimen when the smallest observable cluster of hydrocarbon crystals first occurs upon cooling under prescribed conditions.

DISCUSSION - The cloud point occurs when the temperature of the specimen is low enough to cause hydrocarbon crystals to precipitate. In a homogeneous liquid, the cloud is always noted first at the location in the specimen where the specimen temperature is the lowest. The cloud point is the temperature at which the crystals first occur, regardless of their location in the specimen, and not after extensive crystallization has taken place. The hydrocarbon crystals that precipitate at lower temperatures are typically, but not excluded to, straight chain hydrocarbons commonly called "wax crystals".

DISCUSSION - The purpose of the cloud point method is to detect the presence of the wax crystals in the specimen; however, trace amounts of water and inorganic compounds may be present. The intent of the cloud point method is to capture the temperature at which the liquids in the specimen begin to change from a single liquid phase to a two-phase system containing solid and liquid. It is not the intent of this test method to monitor the phase transition of the trace components, such as water.

coagulate, v - to cause to become viscous or thickened into a coherent mass.
coagulated pentane insolubles, n - in used oil analysis, separated matter that results when a coagulant is added to a solution of used oil in pentane.

DISCUSSION - The addition of a coagulant will aid in separating finely divided materials that may have been held in suspension because of the dispersant characteristics of the oil.

DISCUSSION - This test method uses a 1 % coagulant solution. Test Method D893 uses a 5 % coagulant solution.

coagulated toluene insolubles, n - in used oil analysis, coagulated and separated matter not soluble in pentane or toluene.
coefficient of friction, (µ) - the ratio of the tangential force that is needed to start or to maintain uniform relative motion between two contacting surfaces to the perpendicular force holding them in contact.
coefficient of friction, µ or f, n - in tribology, the dimension-less ratio of the friction force (F) between two bodies to the normal force (N) pressing these two bodies together.
µ or f = (F/N)

DISCUSSION - A distinction is often made between static coefficient of friction and kinetic coefficient of friction.

coefficient of friction µ or f, n - in tribology, the dimension-less ratio of the friction force (Ff) between two bodies to the normal force (Fn) pressing these bodies together.
µ = (Ff/Fn)

coke, n - a carbonaceous solid produced from coal, petroleum, or other materials by thermal decomposition with passage through a plastic state.
cold sticking, n - of piston rings, a condition in which the ring is free in its groove while the engine is running but stuck when the piston is cold, normally indicated by the absence of varnish or other deposits on the outer face of the ring and of signs of blowby on the piston skirt.
cold-stuck piston ring, n - in internal combustion engines, a piston ring that is stuck when the piston and ring are at room temperature, but inspection shows that it was free during engine operation.

DISCUSSION - A cold-stuck piston ring cannot be moved with moderate finger pressure. It is characterized by a polished face over its entire circumference, indicating essentially no blowby passed over the ring-face during engine operation.

combustion chamber, n - in reciprocating internal combustion engines, the volume bounded by the piston crown and any portion of the cylinder walls extending above the piston crown when in the top dead center position, and the inner surface of the cylinder head including any spark plugs and other inserted components.
commercial butane - a hydrocarbon product for use where low volatility is required.
commercial PB mixtures - mixtures of propane and butane for use where intermediate volatility is required.
commercial propane - a hydrocarbon product for use where high volatility is required. Commercial propane is suitable for certain low severity internal combustion engine applications.
compatibility, n - of crude oils or of heavy fuel oils, the ability of two or more crude oils or fuel oils to blend together within certain concentration ranges without evidence of separation, such as the formation of multiple phases.

DISCUSSION - Incompatible heavy fuel oils or crude oils, when mixed or blended, result in the flocculation or precipitation of asphaltenes. Some oils may be compatible within certain concentration ranges in specific mixtures, but incompatible outside those ranges.

compensation line, n - a line of plot on log-log paper where the coordinates are scar diameter in millimetres and applied load in kilograms-force (or newtons) obtained under dynamic conditions.

DISCUSSION - Shown in Fig. 1 as line ABE.

compensation scar diameter, n - the average diameter, in millimetres, of the wear scar on the stationary balls caused by the rotating ball under an applied load in the presence of a lubricant, but without causing either seizure or welding.
composite sample - a thoroughly mixed gross sample.
composite sample - a sample, representative of an entire consignment of calcined petroleum coke, generated by mixing portions of gross samples from different lots together in mass fractions proportioned to the consignment.
compression ratio, n - the ratio of the volume of the combustion chamber including the precombustion chamber with the piston at bottom dead center to the comparable volume with the piston at top dead center.
compressive strength, n - a property of solid material that indicates its ability to withstand a uniaxial compressive load.
congealing point, n - that temperature at which molten petroleum wax ceases to flow, when allowed to cool under prescribed conditions.
congealing point, n - of petroleum wax, that temperature at which molten petroleum wax, when allowed to cool under prescribed conditions, ceases to flow.
consistency, n - of lubricating grease, the degree of resistance to movement under stress.

DISCUSSION - The term consistency is used somewhat synonymously with penetration. Generally, consistency refers to worked penetration of a grease.

consortium (pl. consortia), n - microbial community comprised of more than one, species that exhibits properties not shown by individual community members.

DISCUSSION - Consortia often mediate biodeterioration processes that individual taxa cannot.

continuous analyzer unit cycle time - the time interval required to replace the volume of the analyzer measurement cell.
control limits, n - limits on a control chart that are used as criteria for signaling the need for action or for judging whether a set of data does or does not indicate a state of statistical control.
cool-on-column injector, n - an injection port that allows controlled injection of the sample at a temperature close to or lower than the boiling point of the solvent into the gas chromatographic column or a liner within the injection port connected to the column.

DISCUSSION - After the injection, the injection port is heated at a fixed rate to a temperature sufficiently high enough to allow the transfer of sample components of interest from the injection port to the part of the column located in the gas chromatograph (GC) oven.

corrected load, n - the load in kilograms-force (or newtons) for each run obtained by multiplying the applied load by the ratio of the Hertz scar diameter to the measured scar diameter at that load.
corrected load, n - the load in kilograms-force (or newtons) obtained by multiplying the applied load by the ratio of the Hertz scar diameter to the measured scar diameter at that load.

DISCUSSION - In this test method, the corrected load is calculated for each run.

correction factor, n - a mathematical adjustment to a test result to compensate for industry-wide shifts in severity.
corrosion, n - the chemical or electrochemical reaction between a material, usually a metal surface, and its environment that can produce a deterioration of the material and its properties.
corrosion, n - the chemical or electrochemical oxidation of the surface of metal, which can result in loss of material or accumulation of deposits.[
cracked gases, n - hydrocarbon gases that contain unsaturates.
critical parts, n - those components used in the test that are known to affect test severity.
critical pressure, n - that pressure needed to condense a gas at the critical temperature.
critical temperature, n - highest temperature at which a gaseous fluid can be converted to a liquid by means of compression.
cross-method reproducibility (RXY), n - a quantitative expression of the random error associated with the difference between two results obtained by different operators using different apparatus and applying the two methods X and Y, respectively, each obtaining a single result on an identical test sample, when the methods have been assessed and an appropriate bias-correction has been applied in accordance with this practice; it is defined as the 95 % confidence limit for the difference between two such single and independent results.

DISCUSSION - A statement of cross-method reproducibility must include a description of any bias correction used in accordance with this practice.

DISCUSSION - Cross-method reproducibility is a meaningful concept only if there are no statistically observable sample-specific relative biases between the two methods, or if such biases vary from one sample to another in such a way that they may be considered random effects. (see 6.7.)

crude oil, n - a naturally occurring hydrocarbon mixture, generally in a liquid state, which may also include compounds of sulfur, nitrogen, oxygen, metals, and other elements. (Synonym - crude petroleum, crude.)
cup grease, n - any lubricating grease having physical properties, such as consistency and texture, suitable for its use in spring-loaded or screw-type lubricating cups.

DISCUSSION - Cup greases are predominantly NLGI No. 3 or 4 calcium greases, but grease types other than calcium are also used.

cylinder height, n - for the CFR engine, the relative vertical position of the engine cylinder with respect to the piston at top dead center (tdc) or the top machined surface of the crankcase.
cylinder stock, n - lubricant for independently lubricated engine cylinders, such as those of steam engines and air compressors. Cylinder stock are also used for lubrication of valves and other elements in the cylinder area.