Property and Unit

Property is the quality in a substance or material.

Chemical Property is a characteristic or any quality of a substance that can be measured or observed following the chemical changes or reactions to the substance. Chemical Properties are heat of combustion, reactivity with water, PH, and electromotive force, etc.

Physical Property is a characteristic of the substances that is observed or measured without changing the composition of the substance. The measurement of the Physical Property may change the arrangement of the substance, but not the structure of its molecules. Some Physical Properties are specific for a given substance and can be used to help identify them that includes the colour, smell, boiling point, melting point, infra-red spectrum, viscosity and density, etc.

Extensive Property is a physical property of the substances or objects that depends on the size or quantity of a substance or an object that is present. (e.g., mass, volume, etc.) The Extensive Property can be measured for each subsystem; the value of the property for the system would be the sum of the property for each subsystem.

Intensive Property is the physical property of substances or objects that is independent of the size or quantity of the substance.

Intrinsic Property is the property of object or material that is independent of the quantity, regardless of uses or environmental conditions.

Thermodynamic Property is the properties of a fluid at equilibrium that is measurable, and whose value describes a state of a physical system. The Thermodynamic Property can be reached only when all driving forces for or with composition change, temperature, or pressure are exhausted after an infinite time.

Phase is a homogeneous phase of matter with uniform chemical and physical properties that is a state of substance such as gas, liquid, solid and plasma.

State of Matter is a homogeneous phase of matter that is a state of substance such as gas, liquid, solid and plasma.

Phase Change is the process of the state change of matter of a sample from one physical state (solid, liquid, vapour, and plasma) to another (e.g., liquid to vapour), with a necessary or coincidental input or release of energy.

Gas is a substance or substance mixture that is one of the four fundamental states of matter (gas, solid, liquid, and plasma). The hydrocarbon Gas is used for a fuel or chemical industry.

Liquid is a substance that is the incompressible fluid, flows freely, and a state only by having a definite volume but not a definite shape like water or oil.

Solid is a state of matter characterised that is a hard or firm and keeping a stable shape.

Plasma is 1) the fourth state of matter (solid, liquid, gas, and plasma) that has properties unlike those of the other states. The Plasma is a very hot gas and some or all constituent atoms are split up into electrons and ions, which can move independently of each other; 2) the fluid part of blood and makes up the bulk of the volume.

Sublimation is a solid turning directly into a gas, material changes from a solid to a gas, it never passes through the liquid state. This image shows water in its three forms: ice, water, and steam.

International System (SI) of Unit was created the decimal Metric System at the time of the French Revolution and the subsequent deposition of two platinum standards representing the metre and the kilogram, on 22 June 1799, in the Archives de la République in Paris can be seen as the first step in the development of the present SI Units. International System (SI) of Units are Time: second (s); Length: metre (m); Mass: kilogram (kg); Force: newton (N); Temperature: degree Celsius (°C); Absolute temperature: kelvin (°K). (Refer to the English Unit)

Standard Temperature and Pressure (STP) is the nominal conditions of temperature and pressure in the atmosphere at sea level that is important to physicists, chemists, engineers, and pilots and navigators. The Standard Temperature is defined as zero degrees Celsius (0 °C), which translates to 32 degrees Fahrenheit (32 °F) or 273.15 degrees kelvin (273.15 °K) that is essentially the freezing point of pure water at sea level, in air at standard pressure. The Standard Pressure supports 760 millimetres in a mercurial barometer (760 mmHg) that is about 29.9 inches of mercury, and represents approximately 14.7 pounds per square inch (14.7 lb/in^2). Imagine a column of air measuring one inch square, extending straight up into space beyond the atmosphere. The air in such a column would weigh about 14.7 pounds.

Standard Conditions are the condition specified in a series of scientific tests for experimental measurements to allow comparisons between different sets of data;

IUPAC: a) Standard Temperature and Pressure (STP): Standard Conditions for Gases – Temperature, 273.15 °K (0 °C) and pressure of 10^5 pascals (100 kPa, 1 bar); b) Standard Ambient Temperature and Pressure (SATP) as a temperature of 298.15 °K (25 °C, 77 °F) and an absolute pressure of exactly 100 kPa (1 bar).

NIST: Normal Temperature and Pressure (NTP): uses a temperature of 20 °C (293.15 °K, 68 °F) and an absolute pressure of 101.325 kPa (14.696 psi, 1 atm).

The International Standard (SI) Metric: Conditions for natural gas and similar fluids are 288.15 °K (59.00 °F, 15.00 °C) and 101.325 kPa.

MKS (Metre, Kilogramme, and Second) Unit is a physical metric system of units that expresses any given measurement using fundamental units of the Metre, Kilogramme, and Second (MKS). The MKS Unit system includes the Newton and Joule for the force and energy. (Refer to the Metric System, CGS (Centimetre, Gram and Second) Unit))

CGS (Centimetre, Gram and Second) Unit is a metric system that is based on the centimetre as the unit of length, the gram as the unit of mass, and the second as the unit of time. For the international standardisation and scientific purposes, CGS units have now been replaced by the International Standard (SI) Units. (Refer to the MKS (Metre, Kilogramme, and Second) Unit)

English Unit is the historical units of measurement used in England up to 1824, the units were redefined in the United Kingdom in 1824 by a Weights and Measures Act, which retained many but not all of the unit names and redefined some of the definitions. Some fields of engineering in the United States uses a system of measurement of physical quantities known as the English Engineering units, such as Foot, Pound, and Second (FPS) system of measurement. The English Units are Time: second (sec); Length: foot (ft); Mass: pound mass (lbm); Force: pound force (lbf); Temperature: Degree Fahrenheit (°F) degree; Absolute Temperature: degree Rankine (°R). (Refer to the SI Unit System)

FPS (Foot, Pound, and Second) Unit is a system of measurement of physical quantities known as the English Engineering units.

Imperial Unit is a measurement system of the weight, length, area, and volume that is originally developed in England. (e.g., Length: inches, feet, yards; Area: square feet, acres; Weight: pounds, ounces; Volume: fluid ounces, gallons, pint, etc.) The Imperial Unit System has been replacing by the Metric System in most countries including England, however some imperial units and U.S. Customary units are still used in the United Kingdom, Canada, United States and other countries formerly part of the British Empire.

General Conference on Weights and Measures (CGPM) is the primary intergovernmental treaty organisation responsible for the International Standard (SI), representing nearly 50 countries. It has the responsibility of ensuring that the SI is widely disseminated and modifying it as necessary so that it reflects the latest advances in science and technology.

International Committee for Weights and Measures (CIPM) comes under the authority of the General Conference on Weights and Measures (CGPM). It suggests modifications to the International Standard (SI) to the CGPM for formal adoption. The CIPM may also on its own authority pass clarifying resolutions and recommendations regarding the SI.

U.S. Customary Unit is a measurement system in the United States. The United States Customary Unit system developed from English units and this system measures length in inches, feet, yards, and miles; capacity in cups, pints, quarts, and gallons; weight in ounces, pounds, and tons; and temperature in degrees Fahrenheit.

Numeral System is a writing system for expressing numbers that is a mathematical notation for representing numbers of a given set: Oneness can be represented by the Roman numeral I, by the Greek letter alpha α, or by the modern numeral 1. (Refer to the Numbering System)

Metric System Prefix is a unit prefix that precedes a basic unit of measure to indicate multiples and subdivision of any unit: k (Kilo, 10^3) for Thousand, M (Mega, 10^6) for Million, G (Giga, 10^9) for Billion (but in finance B is for Billion), T (Tera, 10^12) for Trillion, P (Peta, 10^15), E (Exa, 10^18), and m (Milli) form Thousandth)..

Kilo (k) is a decimal unit prefix in the metric system denoting multiplication by one thousand (10^3). It has been used in the International System (SI) of Units where it has the unit symbol k, in lower case.

M is 1) the Roman numeral for one thousand; 2) the International Standard (ISO) defines a million should be abbreviated to M. (Refer to the Metric System Prefix)

MM is a designation that is derived from the Roman numeral M for one thousand meaning "one thousand one thousands" or one million. MM is widely used in the gas industry to mean a million: MMbbl, MMBtu, MMcf, MMcm, MMscf, MMscm.

mm (Millimetre) is an equal to 1/1000 (10^-3) of a metre (m).

Giga (G) is a unit prefix in the metric system denoting a factor of 10^9

Nano is 1) extremely small that can only be seen with a powerful microscope, prefix denotes a factor of one billionth of the stated unit (10^-9). A Nanometre (nm) is a unit of length that is 10^-9 metre; 2) a short for the Nanotechnology.

Nanometre (nm) is a unit of length equal to one thousand-millionth of a metre (10^-9 m).

Nanoscale (or Nano Range) is having one or more dimensions from approximately 1 nm to 100 nm.

Pico- (symbol p) means very small, a unit prefix in the metric system denoting one trillionth, a factor of 10^-12 (0.000000000001).

Parts per Billion (ppb) is the number of mass unit of a contaminant per billion units of total mass, 1/1,000,000,000.

ppm is one part per million, 1/1,000,000.

Zero is no quantity or number, and the arithmetical symbol is '0'

bp (Basis Point) is 1) one hundredth of 1 percentage point that is a unit of measure used in finance to describe the percentage change in the rate, index, or other benchmark. Changes of interest rate is often stated in basis points. One Basis Point is equivalent to 0.01% (1/100th of a percent) or 0.0001 in decimal form. (e.g., an interest rate of 10% increased by 1 bp, it changed to 10.01%); 2) BP plc (formerly The British Petroleum Company) is a British oil and gas company headquartered in London, England.

Quantum Number is the value used to describe the energy levels of atoms or molecules. There is a total of four quantum numbers: the principal quantum number (n), the orbital angular momentum quantum number (l), the magnetic quantum number (ml), and the electron spin quantum number (ms).

Numbering System is a system of naming or representing numbers, as the decimal system or the binary system. (Refer to the Numeral System)

C3. Length (Metre (Meter, m)); Area; Volume

Length is a physical quantity of a geometric measurement between two points, the International Standard (SI) unit is a Metre (m), and equal to 3.281 foot.

Metre (Meter, m) is the base unit of length in the International System (SI) of Units that is the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second. mm (Millimetre) is equal to one-thousandth (1/1000, 10^-3) of a metre (m). cm (Centimetre) is equal to one-hundredth (1/100, 10^-2) of a metre (m). km (Kilo) equals to one thousand (1,000, 10^3) of a metre (m).

Inch (in or ″) is a unit of the length in the Imperial and U.S. Customary Systems of Measurement. The international inch is exactly 25.4 mm. There are 12 inches in a foot and 36 inches in a yard.

Micrometre (µm) is a unit of length equal to one thousandth of a millimetre or one millionth of a metre (10^-3 mm or 10^-6 m). Approximately 0.00004 inches.

Area
Area is a physical quantity and extent surface, a two dimensional shape. The International Standard (SI) of Units of the area is a square meter (m^2), equal to 10.764 ft^2.

Hectare (ha) is the International Standard (SI) accepted metric system unit of area equal to 100 ares (10,000 m2) and primarily used in the measurement of land. An acre is about 0.405 hectare and one hectare contains about 2.47 acres.

Volume
Volume is a physical quantity of three dimensional space or a substance occupied by a solid, liquid, or gas. The International Standard (SI) of Units of a Volume is a cubic metre (m^3), equal to 1,000 Litres.

Cubic means being the volume of a cube whose edge is a specified unit.

cm (Cubic Metre, M3), Mcm, Bcm is the unit of volume in the International System (SI) of Units: 1 M3 = 1000 litres ≈ 35.3 ft3 ≈ 6.29 Oil Barrels. Mcm means one thousand cubic metres, and Bcm means billion cubic metres.

C4. Mass (Weight)

Mass means 1) a large number; 2) the amount of matter in any solid object or in any volume of liquid or gas.

Weight is 1) to measure the heaviness of an object; 2) the Weight of an object is defined as the force of gravity on the object and may be calculated as the mass times the acceleration of gravity, W = m * g. The unit of measurement for the Weight is a force, its International Standard (SI) of Unit is the Newton (N).

Kilogram (kG) is the base unit of mass in the International System (SI) of Units that is the fixed numerical value of the Planck constant h to be 6.626 070 15 × 10^-34. Gram (G) equals to one-thousandth (10^-3) Kilogram (kG); Milligram (mG) is 10^-6 of a Kilogram (kG).

C5. Time

Time is 1) a part of existence or indefinite continued progress of existence that is measured in second (s), minutes, days, years, etc.; 2) to be done as a plan, schedule, arrangement, or should happen; 3) 4th Dimension (Dimensions: length, width, height, and duration (time).

Second (s) is the base unit of time in the International System (SI) of Units that is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the Cesium (CS) 133 atom.

Half-life (t1⁄2) is the time required for a quantity to reduce to half its initial value, usually the atoms of a radioisotope to decay and becomes an isotope of another element. The nuclei of radioactive atoms are unstable that breaks down and changes into a completely different type of atom. There are three main types of radiation, called alpha, beta and gamma radiation, which all have different properties. The half-life of a radioactive isotope is the time taken for half its radioactive atoms to decay. Also, the Half-life is applied in the medical sciences, the biological half-life of drugs and other chemicals in the body.

C6. Temperature (Thermodynamic Temperature: Kelvin)

Temperature is a comparative amount of heat in a substance that is a measure of the kinetic energy of its particles, place or body. Temperature influences various physical and chemical properties of materials and is crucial in numerous scientific, industrial, and everyday applications. Several scales and units exist for measuring temperature, the most common being Celsius (°C; formerly called centigrade), Fahrenheit (°F), and, especially in science, Kelvin (°K).

Celsius (°C) is an International Standard (SI) of Units of the temperature, 0 °C is the freezing of water and 100 °C is the boiling point of water. A Conversion to Celsius from Fahrenheit: °C = (°F - 32) x 5/9, where °F is the temperature in Fahrenheit.

Fahrenheit (°F) is an English Unit of the temperature, 32 °F is the freezing of water and 212 °F is the boiling point of water. A Conversion to Fahrenheit from Celsius: °F = 9/5°C + 32, where °C is the temperature in Celsius (°C).

C7. Pressure

Pressure is 1) an action of a continuous physical force against an object or opposing force (symbol: p or P), and the International Standard (SI) of Units of the pressure is the pascal (Pa), equivalent to one newton per meter squared (N * m^-2); 2) a strong, often threatening influence on an organisation or person.

Pascal (Pa) is the International Standard (SI) of derived units of the pressure or stress: 1 Pa = 1 N/m^2 = 1 kG/(m * s^2) = 1 J/m^3. The unit of measurement called standard atmosphere (atm) is defined as 101,325 Pa. Kilopascal (kPa) equals to 1000 Pa, and Hectopascal (1 hPa = 100 Pa) is equal to one millibar.

Bar (bar) is a metric unit of gas pressure that is defined as exactly equal to 100,000 Pa (N/m^2) which is approximately atmospheric pressure (1 atm).

C8. Power or Force (Newton (N))

Force is 1) a physical power and influence that changes movement; 2) in science, the Force (F) has a magnitude and direction that is measured in the International Standard (SI) unit of Newton (N).

Power is 1) the amount of energy available or capacity to do a work, measured in Horsepower, Watts, Btu per hour, or Electric power (electric current and electromotive force); 2) to control a work or an organisation.

Newton (N) is the International Standard (SI) of Units of the force: m * kG * s^-2

C9. Heat (Energy, Work: Joule)

Heat (Q or q) is a form of energy that flows between two objectives of matter due to their difference in temperature. The standard unit of heat in the International System (SI) of Units is the calorie (cal), which is the amount of energy transfer required to raise the temperature of one gram (G) of pure liquid water by one degree Celsius (°C).

Calorie (cal) is an amount of heat required to raise the temperature of 1 gram of water by 1 degree Celsius (°C). The Calorie is an amount of energy equal to exactly 4.184 joules (J). Kcal (Kilocalorie) is equals to 1,000 calories (cal); Mcal (Megacalorie) is equals to 10^6 calories (cal).

Joule (J) is an International Standard (SI) of Units of energy, work, force, quantity of heat. It is equal to the energy transferred (or work done) to an object when a force of one newton acts on that object in the direction of its motion through a distance of one metre (1 newton metre or N·m): m2·kg·s-2. 1 J is equal to 1×10^7 erg (exactly), 0.2390 cal (gram calories), 9.4782×10^-4 BTU, 2.7778×10^-7 kilowatt-hour. kJ (Kilojoule) equals to one thousand Joules (J); MJ (MegaJoule) equals to one million (10^6) Joules (J)

C10. Electric Units

Ampere (A) is the base unit of electrical current or rate of flow of electrons in the International System (SI) of Units that flows in a circuit at an electromotive force of one Volt and at a resistance of one Ohm.

Ampere Hour (Ah/AH) Meter is an instrument that measures the flow of current with time. (Refer to the Ampere Hour (or Amp-Hours, Ah/AH))

Current (I) is a flow of electrical charge carriers, usually electrons or electron-deficient atoms.

C11. Radiation

Radiation is an emission or transmission of energy in the form of waves or particles through space or through a material medium. The Radiation is from a source such as the light, heat and sound, etc. The Radiation is energy given off by matter in the form of rays or high-speed particles that is composed of atoms. (Refer to the Thermal Radiation; Solar Radiation)

Irradiance is the direct, diffuse, and reflected solar radiation received by a surface that is the flux of radiant energy per unit area, and the SI unit of irradiance is the watt per square metre (W/m2).

Becquerel (Bq) is an International Standard (SI) unit of the intrinsic radioactivity in a material: 1/S. One Bq indicates one radioactive decay per second. Because this is a very small amount, radioactivity is usually measured in GBq or TBq. Another measure of radioactivity, the curie, is equivalent to 37 billion Bq.

C12. Light (Brightness)

Light means 1) the making the things visible with the brightness that comes from the sun, fire, electrical devices; 2) not weighing a lot.

Lumen (lm) is the International Standard (SI) of Units of the quantity of light of the Luminous or Luminous flux that is a measure of the total quantity of visible light emitted by a source per unit of time. The higher the Lumen rating the brighter the lamp will appear. 1 Lumen (lm) = 1 Candela (cd) x Steradian (sr) (A solid angle of one steradian (sr), from a source that discharges to an equal light in all directions, with the strength of one candela (cd)).

Luminance (Unit: lumen) is the intensity of light emitted from a surface per unit area in a given direction that is the physical measure of the subjective sensation of brightness.

C13. Density and Gravity

Density is a mass of a unit of volume that is often expressed as mg/L.

Relative Density (or Specific Gravity) is the ratio of density of a substance to the density of a given reference material (e.g., water or air) at the same standard pressure and temperature.

Mass Density is a physical quantity of a mass of a particular substance per unit, and the International Standard (SI) of Units of a Mass Density is a kilogram per cubic metre: kg/m^3.

C14. Concentration

Concentration means 1) in chemistry is a physical quantity and an abundance of a particular substance in a total mixture, and an International Standard (SI) unit of a concentration is a mole per cubic meter (mol/m3); 2) to think carefully about one thing, nothing else.

Milligrams per Liter (mg/l) is a unit of the concentration of a constituent in water or wastewater.

Maximum Allowable Concentration (MAC) is the criteria of safe levels of exposure to a hazardous or toxic process, chemical, etc., that can be used to establish the acceptability of working conditions.

C15. Velocity

Velocity is a physical quantity of a speed, and the International Standard (SI) of Units of the Velocity is a Metre per Second (m/s) that equals to 2.23696 Mile per Hour.

Knot (kn or kt) is a unit of speed at which a vessel will travel one nautical mile (1.852 km) per hour, approximately 1.151 mph.

Mach Number (M or Ma) is a dimensionless quantity representing the ratio between the speed of an object and the speed of sound at ambient temperature and pressure.

C16. Atom and Molecule

Atom is the smallest unit of a substance consists of a nucleus of protons and neutrons with electrons orbiting. The identity of a substance will be destroyed if its atom is further divided, and different substances will have different types of atoms. Atoms can combine to form a molecule. The Atom that loses or gains electrons is called an ion.

Atomic Mass (Symbol: m or ma, Unit: Da, u, kg, g) is 1) the total mass of the protons, neutrons, and electrons in a single atom; 2) the average mass of atoms of an element. (Refer to the Atomic Mass Unit (amu))

Atomic Mass Unit (amu) is a physical constant equal to 1/12 of the mass of an unbound atom of carbon-12. The carbon-12 (C-12) atom has six protons and six neutrons in its nucleus. In the modern usage 1 amu (Atomic Mass Unit) = 1 u (unified atomic mass unit) = 1 Da (Dalton) = 1 g/mol, Symbol: m or ma).

C17. Acid and Alkali

Acid is a chemical agent that releases hydrogen ions when added to water. The term pH, which in general is the measure of the number of acidity or alkalinity that is in a solution. More specifically, it is a measure of the amount of protons or hydrogen ions that are present in an aqueous solution. An acid has a pH of less than 7. (Opposite of the Alkali or Alkaline)

Alkali is a substance that releases hydroxide ions (OH -) in water. An alkali has a pH of more than 7 or having hydroxide ions greater than 10^-7. (Also, called as the Alkaline, Opposite of the Acid)

Acid Number is a number indicating the amount of free acid present in a substance that is the number of milligrams of potassium hydroxide (KOH) required to neutralise the free acids of 1 gram of chemical substance, generally for the non-volatile content.

ined with litmus that indicates pH, or acidity, or alkalinity of a substance. The Litmus Paper turns red under acidic conditions and blue under alkaline conditions.

C18. Permeability

Permeability is the ability measurement of material to allow the passage of a liquid, such as water through rocks.

Absolute Permeability is the ability to flow or transmit fluids through a substance such as a rock that indicates the flow capacity of formation.

Porosity is a percentage of pore volume or void space that is the proportion of a rock volume occupied by the voids between mineral grains.

C19. Petroleum Product

Cetane Number (CN) of Cetane Rating is a standard measure of the ignition value of a diesel fuel that represents the percentage by volume of cetane in a combustible mixture. The higher Cetane Number, the easier it is to start a standard (direct-injection) diesel engine. A CN is a factor in determining the quality of diesel fuel including energy content, density, lubricity, cold-flow properties and sulphur content.

Diesel Index is the Cetane Number that calculates multiplying the API gravity by the aniline point of a Diesel fuel, divided by 100.

Octane Number or Octane Rating is a standard measure of a fuel's ability to resist knock that denotes the percentage (by volume) of iso-octane (a type of octane) in a combustible mixture (from iso-octane (100) and heptane (0)). The Octane requirement of an engine varies with compression ratio, geometrical and mechanical considerations, and operating conditions. The higher the octane number the greater the fuel’s resistance to knocking or pinging during combustion.

C20. Humidity

Humidity is an amount of water vapour in the air. A water vapour is the gaseous state of water and is invisible.

Absolute Humidity is the ratio of the mass of water vapor (moisture) to the air volume that occupies by a mixture of water vapor and dry air at a specific temperature: g/m3.

Relative Humidity is a measurement of moisture content in the air or amount of water vapour (moisture) in the air compared to the maximum amount that the air could hold at a given temperature. The Relative Humidity is expressed as a percentage, so the maximum is 100 %.

C21. Hardness

Hardness is 1) resistance of a material to plastic deformation, usually by indentation which is determined by a standard test where the surface resistance to indentation is measured. The Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity (Refer to the Brinell Hardness); 2) a water-quality indication of the concentration of inorganic polyvalent cations (generally calcium and magnesium) in water. (Refer to the Water Hardness)

Barcol Hardness is a hardness value of the rubber, plastic, or coating materials that measures the depth of penetration of an indentor loaded on the materials, and compares to a reference material.

Brinell Hardness is the hardness of a metal or alloy measured by hydraulically pressing a hard ball under a standard load into the specimen that is the ability of a material to resist permanent indentation deformation. BHN = Brinell Hardness Number (kgf/mm2) The Brinell Hardness is measured in accordance with ISO 6506-1 or Test Method E10, using a 1 to 10 mm diameter tungsten carbide ball and a force of approximately 9.807 to 29.420 N (1 to 3000 kgf).

C22. Flow Rate and Capacity

Cubic Feet per Second (CFS) is a rate of the flow, in streams and rivers that is an Imperial unit and U.S. customary unit volumetric flow rate.

Flow Coefficient (Cv) is a relative measure of the fluid flow efficiency that is a designing factor which relates head drop (Δh) or pressure drop (ΔP) across the valve with the flow rate (Q). The Cv is the number of gallons of water per minute (gpm) will flow through a valve or any other restricting device at a temperature of 60ºF with a pressure drop across the valve of 1 psi. (Cv = 1.156 * Kv). (Refer to the Flow Factor (Kv))

Flow Factor (Kv) is the flow coefficient in metric units that is defined as the flow rate in cubic meters per hour (m3/h) of water at a temperature of 16ºC with a pressure drop across the valve or any other restricting device of 1 bar. The Kv is related the head drop (Δh) or pressure drop (ΔP) across the valve with the flow rate (Q). (Kv = 0.865 * Cv) (Refer to the Flow Coefficient (Cv))

C23. Computer related Units

Bit is 1) a small piece, part, or quantity of something; 2) a unit of information in a computer that must be either 0 or 1.

Bits per Second (BPS) is a measure of transfer speed in digital communication networks. One kilobit per second (Kbps) equals 1,000 bits per second (bps). One megabit per second (Mbps) equals 1000 Kbps or one million bps. One gigabit per second (Gbps) equals 1000 Mbps, one million Kbps or one billion bps.

Byte is a unit of measurement used to measure data. One byte contains eight binary bits operated on as a unit of computer storage from personal computers to mainframes that holds the equivalent of a single character, such as the alphabet and other characters.

Absorptivity is 1) a measure of the ability of a material to absorb radiation by a surface to the total radiation incident on the surface, in chemistry; 2) a measure of how strongly a chemical species absorbs light at a particular wavelength.

Alcohol Proof is a measurement of alcohol content that contained a certain higher amount of alcohol: in the UK, it was equal to about 1.75 times the Alcohol by Volume (ABV), and in the USA, alcohol proof is defined as twice the percentage of ABV.

Blood Alcohol Concentration (BAC) is the relative proportion of ethyl alcohol (C2H5OH) in the blood based upon the number of grams of alcohol per 100 millilitres of blood, and often expressed as a percentage. The UK legal limit for drivers with a blood alcohol concentration (BAC) is 80 mg of alcohol per 100 ml of blood, in US terms this would be expressed as 0.08%.

Catalyst Activity (z) is an increase in rate of a chemical reaction caused by the presence of a catalyst. The Catalytic Activity is usually denoted by the symbol z and measured in mol/s, a unit which was called katal and defined the International Standard (SI) unit for catalytic activity.

Katal (kat) is an International Standard (SI) unit of the catalytic activity: s-1·mol

Compressibility is the ratio of the percent change in volume to the change in pressure that is a measure of the relative volume change of a fluid or solid.

Conductivity is a measure of a material's ability to conduct an electric current or heat (thermal conductivity).

Darcy

A is 1) a symbol of the Ampere which is an International Standard (SI) unit of the electric current (I) (Refer to the Ampere (A)); 2) a Mass Number of an atom (the sum of the number of protons and neutrons in the atomic nucleus).

Abel Tester (or Abel Closed-Cup Tester) is a laboratory instrument of the closed cup flash tester that works by heating a small sample of the liquid in a closed cup until its vapours ignite when exposed to an open flame. The Abel Tester is used to test the flash point of kerosene and other potential hazards of liquid which have a flash point of -30°C ~ 70°C. The flash point is the lowest temperature at which the vapours of a liquid will ignite when exposed to an open flame or another ignition source.

Abrasion Resistance is the ability of a material to resist or maintain its original surface by rubbing or wear.

Absolute Difference is a difference between the values regardless to sign (positive or negative value) of two variables that describes the distance on the real line between the points.

Acoustic Emission is the phenomenon of radiation of acoustic waves produced by deformation or brittle failure of material and characterized by relatively high frequency.

Air Mass is 1) a large volume of air which travels from one area to another; 2) an indication of the length of the path solar radiation travels through the atmosphere.

Allotrope is a form of a chemical elemental that exist in the same state (solid, liquid or gas) but have different properties. (e.g., carbon solid: graphite, charcoal, and diamond)

Altitude is a vertical height of location or position from the base (bench mark, datum), normally the sea level.

Amphoteric

International Bureau of Weights and Measures (BIPM), located outside Paris, has the task of ensuring worldwide unification of physical measurements. It is the international metrology institute, and operates under the exclusive supervision of the CIPM (International Committee for Weights and Measures). (Source: http://physics.nist.gov)

National Institute of Standards and Technology (NIST) was founded in 1901 and now part of the U.S. Department of Commerce, NIST is one of the nation's oldest physical science laboratories. Congress established the agency to remove a major handicap to U.S. industrial competitiveness at the time, a second-rate measurement infrastructure that lagged behind the capabilities of the United Kingdom, Germany, and other economic rivals. Today, NIST measurements support the smallest of technologies, nanoscale devices so tiny that tens of thousands can fit on the end of a single human hair, to the largest and most complex of human-made creations, from earthquake-resistant skyscrapers to wide-body jetliners to global communication networks. (www.nist.gov)

Property and Unit

A. Definition

B. Phase of Matter

C. Unit

C1. Standard Units

C2. Number

C3. ~ C23. Major Units

C24. Other Units

D. Additional Definitions

E. Institute

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