ASTM D4175 Terminology Relating to Petroleum, Petroleum Products, and Lubricants
B6 to B20, n - fuel blend consisting of 6 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.

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.

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 dioxide and methane) to complex polymers, including plastics. Oxygen requirements range from obligate anaerobes, which die on contact with oxygen, to obligate aerobes, which die if oxygen pressure falls below a species specific threshold.

base number, n - the quantity of an acid, expressed in terms of the equivalent number of milligrams of potassium hydroxide per gram of sample, that is required to titrate a sample dissolved in the specified solvent to a specified end point (for example, Test Method D4739).

DISCUSSION - This method uses fixed amounts of isooctane and alcoholic hydrochloric acid as the sample solvent and the end point is defined as the amount of titrant required to reach a yellow end-point with a methyl red indicator solution.

base number - the quantity of perchloric acid expressed in terms of the equivalent number of milligrams of potassium hydroxide that are required to titrate 1 g of the sample dissolved in the specified solvent to a well-defined inflection point as specified in this test method.
base number, n - the quantity of acid, expressed in milligrams of potassium hydroxide per gram of sample that is required to titrate a sample to a specified end point.

DISCUSSION - In this test method, the indicator is p-naphtholbenzein titrated to an orange end point in a toluene-water-isopropanol solvent.

base numbers, n - the quantity of acid, expressed in milligrams of potassium hydroxide per gram of sample that is required to titrate a sample, dissolved in a specified solvent to a specified end point.

DISCUSSION - In this test method, the sample is titrated to a meter reading corresponding to a freshly prepared nonaqueous acidic buffer solution.

base oil, n - a base stock or a blend of two or more base stocks used to produce finished lubricants, usually in combination with additives.
base stock, n - a hydrocarbon lubricant component, other than an additive, that is produced by a single manufacturer to the same specifications (independent of feed source or manufacturer's location), and that is identified by a unique formula number or product identification number, or both.
basicity, n - the quality, state or degree of being basic.

DISCUSSION - In this test method, the criterion for basicity is a pink or red color when phenolphthalein indicator is used.

basis weight of paper, n - basis weight is expressed in grams per square metre. In countries where the metric system is not universal, basis weight is also expressed in pounds per ream.

DISCUSSION - For factors to convert basis weight in grams per square metre to other commercial terms, see Test Method D646.

BDC, n - bottom dead center
bias, n - the difference between the population mean of the test results and an accepted reference value.
bias, n - a systematic error that contributes to the difference between a population mean of the measurements or test results and an accepted reference or true value.
bias, relative, n - the difference between the population mean of the test results and an accepted reference value, which is the agreed upon value obtained using an accepted reference method for measuring the same property.
binder, n - a substance, usually an organic material such as coal tar pitch or petroleum pitch, used to bond the coke or other filler material prior to baking.
bioaccumulation, n - the net accumulation of a substance by an organism as a result of uptake from all environmental sources.
bioburden, n - the level of microbial contamination (biomass) in a system.

DISCUSSION - Typically, bioburden is defined in terms of either biomass or numbers of cells per unit volume or mass or surface area material tested (g biomass / mL; g biomass / g; cells / mL sample, and so forth). The specific parameter used to define bioburden depends on critical properties of the system evaluated and the investigator's preferences.

biocide, n - a poisonous substance that can kill living organisms.

DISCUSSION - Biocides are further classified as bactericides (kill bacteria), fungicides (kill fungi), and microbiocides (kill both bacteria and fungi). They are also referred to as antimicrobials.

biodegradability, n - ability of a substance to be broken down into simpler substances by bacteria.
biodegradable, n - any substance containing < 10 % wt. O2 content which undergoes ≥60 % biodegradation as theoretical CO2 in 28 days and ≥67 % biodegradation as theoretical O2 uptake in 28 days, or any hydraulic fluid containing ≥10 % wt. O2 content which undergoes ≥60 % biodegradation as theoretical CO2 or as theoretical O2 uptake in 28 days.
biodegradation, n - the process of chemical breakdown or transformation of a material caused by organisms or their enzymes.

DISCUSSION - Biodegradation is only one mechanism by which materials are removed from the environment.

biodegradation, n - the process of chemical breakdown or

transformation of a substance caused by organisms or their enzymes.

DISCUSSION - Biodegradation is only one mechanism by which materials are transformed in the environment.

biodeterioration, n - the loss of commercial value or performance characteristics, or both, of a product (fuel) or material (fuel system) through biological processes.
biodiesel, n - fuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, designated B 100.

DISCUSSION - Biodiesel is typically produced by a reaction of vegetable oil or animal fat with an alcohol such as methanol or ethanol in the presence of a catalyst to yield mono-esters and glycerin. The fuel typically may contain up to 14 different types of fatty acids that are chemically transformed into fatty acid methyl esters (FAME).

DISCUSSION - biodiesel, as defined above, is registered with the U.S. EPA as a fuel and a fuel additive under Section 211(b) of the Clean Air Act. There is, however, other usage of the term biodiesel in the marketplace. Due to its EPA registration and the widespread commercial use of the term biodiesel in the U.S. marketplace, the term biodiesel will be maintained for this specification.

DISCUSSION - Biodiesel is typically produced by a reaction of a vegetable oil or animal fat with an alcohol such as methanol or ethanol in the presence of a catalyst to yield mono-alkyl esters and glycerin, which is removed. The finished biodiesel derives approximately 10 % of its mass from the reacted alcohol. The alcohol used in the reaction may or may not come from renewable resources.

biodiesel (B-100), n - fuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats.
biodiesel blend, n - a blend of biodiesel fuel with petroleum-based diesel fuel designated BXX, where XX is the volume % of biodiesel.
biodiesel blend, BXX, n - a blend of biodiesel fuel with petroleum-based diesel fuel.

DISCUSSION - In the abbreviation BXX, the XX represents the volume percentage of biodiesel fuel in the blend.

biodiesel blend (BXX), n - blend of biodiesel fuel with diesel fuel oils.

DISCUSSION - In the abbreviation BXX, the XX represents the volume percentage of biodiesel fuel in the blend.

biodiesel blend (BXX), n - blend of biodiesel fuel with petroleum-based diesel fuel designated BXX, where XX is the volume percentage (as a whole number without the percentage sign) of biodiesel.
biodiesel fuel, n - synonym for biodiesel.
biofilm, n - a film or layer of microorganisms, biopolymers, water, and entrained organic and inorganic debris that forms as a result of microbial growth and proliferation at phase interfaces (liquid-liquid, liquid-solid, liquid-gas, and so forth). (Synonym - skinnogen.)
bio-kinetic model, n - model that can predict the biodegradability of a lubricant.
biomass, n - any material, excluding fossil fuels, which is or was a living organism or component of a living organism.
biomass, n - density of biological material per unit sample volume, area, or mass (g biomass / g (or / mL or / cm2) sample).
biosurfactant, n - a biologically produced molecule that acts as a soap or detergent.
bituminous material, n - in petroleum technology, a black or dark-colored very viscous liquid or semi-solid composed principally of high molecular weight condensed aromatic, or naphthenic compounds, or both.
black oil, n - lubricant containing asphaltic materials. Black oils are used in heavy-duty equipment applications, such as mining and quarrying, where extra adhesiveness is desired.
blank, n - in biodegradability testing, a test system containing all system components with the exception of the test substance.
blank, n - a flask containing the test medium and the inoculum with no additional carbon source added.
bleed (bleeding), n - of lubricating greases, the separation of a liquid lubricant from a lubricating grease for any cause.
blind reference oil, n - a reference oil, the identity of which is unknown by the test facility.

DISCUSSION - This is a coded reference oil which is submitted by a source independent from the test facility.

blowby, n - in internal combustion engines, the combustion products and unburned air-and-fuel mixture that enter the crankcase.
blowby, n - in internal combustion engines, that portion of the combustion products and unburned air/fuel mixture which leaks past piston rings into the engine crankcase during operation.
boilup rate, n - in column distillation, the quantity of vapor entering the column per unit of time.
boilup rate, n - the quantity of vapor entering the column per unit of time.

DISCUSSION - It is expressed in millilitres of liquid per hour for a given column or in millilitres per hour per square centimetre of cross-sectional area for comparative purposes. In the latter case, it refers to the test mixture of n-heptane and methylcyclohexane in the efficiency evaluation (see Annex A1) and is measured at the bottom of the column. The maximum boilup of the n-heptane-methylcyclohexane test mixture is that which the column can handle under stable conditions without flooding. In routine adiabatic operation, the boilup rate can be estimated roughly from the takeoff rate multiplied by the reflux ratio plus one.

bond, v - to connect two parts of a system electrically by means of a conductive wire to eliminate voltage differences.
bonded glycerin, n - is the glycerin portion of the mono-, di-, and triglyceride molecules.
borderline pumping temperature, n - the lowest temperature at which the critical yield stress or critical viscosity that allows a fluid to be pumped occurs.
Bourdon spring gauge, n - pressure measuring device that employs a Bourdon tube connected to an indicator.
Bourdon tube, n - flattened metal tube bent to a curve that straightens under internal pressure.
break-in, n - in tribology, an initial transition process occurring in newly established wearing contacts, often accompanied by transients in coefficient of friction or wear rate, or both, that are uncharacteristic of the given tribological system's long term behavior. (Synonym - run-in, wear-in.)
brake mean effective pressure, n - for spark-ignition engines, the measure of engine power at the output shaft as typically measured by an absorption dynamometer or brake.
bromine index, n - the number of milligrams of bromine that will react with 100 g of sample under the conditions of the test.
bromine number, n - the number of grams of bromine that will react with 100 g of the sample under the conditions of the test.
BSOC, n - break specific oil consumption
BTDC, adj - abbreviation for Before Top Dead Center; used with the degree symbol to indicate the angular position of the crankshaft relative to its position at the point of uppermost travel of the piston in the cylinder.
BTDC (before top dead center), adj - the angular position of the crankshaft relative to its o position at the point of uppermost travel of the piston in the cylinder, used with the degree symbol (°).
bulk sample, n - a large sample, either from one place or made up of several incremental samples of the same material.
bulk sample - the reduced and divided representative portion of the gross sample as prepared for shipment to and received by a laboratory to be prepared for analysis.
Bunsen coefficient, n - the solubility of a gas expressed as the volume, reduced to 273 K (32°F) and 101.3 kPa (1 atm), dissolved by one volume of liquid at the specified temperature and 101.3 kPa.
Bunsen coefficient, n - the solubility of a gas, expressed as the gas volume reduced to 273 K (32°F) and 0.10 MPa (1 atm), dissolved by one volume of liquid at the specified temperature and 0.10 MPa.
burn, vt - in emission spectroscopy, to vaporize and excite a specimen with sufficient energy to generate spectral radiation.
burner fuel oil, n - any petroleum liquid suitable for the generation of heat by combustion in a furnace or firebox as a vapor or a spray, or a combination of both.

DISCUSSION - Different grades are characterized primarily by viscosity ranges.