Electric current (I) is the directional movement of electric charges (ions in electrolytes, conduction electrons in metals).
A necessary condition for the flow of electric current is the closedness of the electric circuit.
Electric current is measured in amperes (A).
The derived current units are:
1 kiloampere (kA) = 1000 A;
1 milliampere (mA) 0.001 A;
1 microampere (μA) = 0.000001 A.
A person begins to feel a current of 0.005 A passing through his body. A current greater than 0.05 A is dangerous to human life.
Electric voltage (U) called the potential difference between two points of the electric field.
Unit electrical potential difference is a volt (V).
1 V = (1 W): (1 A).
The derived voltage units are:
1 kilovolt (kV) = 1000 V;
1 millivolt (mV) = 0.001 V;
1 microvolt (μV) = 0.00000 1 V.
Resistance of a section of an electrical circuit called a value that depends on the material of the conductor, its length and cross-section.
Electrical resistance is measured in ohms (ohms).
1 ohm = (1 V): (1 A).
Derived resistance units are:
1 kiloOhm (kOhm) = 1000 Ohm;
1 megaohm (megohm) = 1,000,000 ohm;
1 milliohm (mOhm) = 0.001 ohm;
1 microohm (μohm) = 0.00000 1 ohm.
The electrical resistance of the human body, depending on a number of conditions, ranges from 2000 to 10,000 ohms.
Specific electrical resistance (ρ) called the resistance of a wire with a length of 1 m and a cross-section of 1 mm2 at a temperature of 20 ° C.
The reciprocal of specific resistance is called electrical conductivity (γ).
Power (P) called the value characterizing the speed at which the transformation of energy occurs, or the speed at which the work is done.
The power of the generator is a quantity that characterizes the speed at which mechanical or other energy is converted into electrical energy in the generator.
Consumer power is a value that characterizes the rate at which the transformation of electrical energy in individual sections of the circuit into other useful types of energy occurs.
The SI system unit of power is watt (W). It is equal to the power at which 1 joule of work is performed in 1 second:
1W = 1J / 1sec
Derived units of measurement of electrical power are:
1 kilowatt (kW) = 1000 W;
1 megawatt (MW) = 1,000 kW = 1,000,000 W;
1 milliwatt (mW) = 0.001 W o1i
1 horsepower (hp) = 736 W = 0.736 kW.
Units of measurement of electrical energy are:
1 watt-second (W sec) = 1 J = (1 N) (1 m);
1 kilowatt-hour (kWh) = 3, b 106 W sec.
Example. The current consumed by an electric motor connected to a 220 V network was 10 A for 15 minutes. Determine the energy consumed by the engine.
W * sec, or, dividing this value by 1000 and 3600, we get energy in kilowatt-hours:
W = 1980000 / (1000 * 3600) = 0.55kW * h
Table 1. Electrical quantities and units
The way of setting temperature values is a temperature scale. Several temperature scales are known.
- Kelvin scale(named after the English physicist W. Thomson, Lord Kelvin).
Unit designation: K(not "degree Kelvin" and not ° K).
1 K = 1 / 273.16 - part of the thermodynamic temperature of the triple point of water, corresponding to the thermodynamic equilibrium of a system consisting of ice, water and steam. - Celsius(named after the Swedish astronomer and physicist A. Celsius).
Unit designation: ° С .
In this scale, the temperature of ice melting at normal pressure is taken equal to 0 ° C, the boiling point of water is 100 ° C.
The Kelvin and Celsius scales are related by the equation: t (° C) = T (K) - 273.15. - Fahrenheit(D.G. Fahrenheit - German physicist).
Unit designation: ° F... It is widely used, in particular in the USA.
The Fahrenheit scale and the Celsius scale are linked: t (° F) = 1.8 t (° C) + 32 ° C. Absolute 1 (° F) = 1 (° C). - Reaumur scale(named after the French physicist R.A. Reaumur).
Designation: ° R and ° r.
This scale is almost out of use.
Ratio with degrees Celsius: t (° R) = 0.8 t (° C). - Rankin scale (Rankin)- named after the Scottish engineer and physicist W. J. Rankin.
Designation: ° R (sometimes: ° Rank).
The scale is also used in the United States.
The temperature on the Rankin scale correlates with the temperature on the Kelvin scale: t (° R) = 9/5 · T (K).
The main temperature indicators in units of measurement of different scales:
The SI unit is meter (m).
- Non-system unit: Angstrem (Å). 1Å = 1 10-10 m.
- Inch(from the Dutch duim - thumb); inch; in; ´´; 1´ = 25.4 mm.
- Hand(English hand - hand); 1 hand = 101.6 mm.
- Link(English link - link); 1 li = 201.168 mm.
- Spahn(English span - span, span); 1 span = 228.6mm.
- Foot(English foot - foot, fеt - feet); 1 ft = 304.8 mm.
- Yard(English yard - yard, corral); 1 yd = 914.4 mm.
- Fatom, fesom(English fathom - a measure of length (= 6 ft), or a measure of the volume of wood (= 216 ft 3), or a mountain measure of an area (= 36 ft 2), or fathom (Ft)); fath or fth or Ft or ƒfm; 1 Ft = 1.8288 m.
- Cheyne(English chain - chain); 1 ch = 66 ft = 22 yd = = 20.117 m.
- Furlong(English furlong) - 1 fur = 220 yd = 1/8 mile.
- Mile(English mile; international). 1 ml (mi, MI) = 5280 ft = 1760 yd = 1609.344 m.
The unit of measurement in SI is m 2.
- Square foot; 1 ft 2 (also sq ft) = 929.03 cm 2.
- Square inch; 1 in 2 (sq in) = 645.16 mm 2.
- Square veil (fesom); 1 fath 2 (ft 2; Ft 2; sq Ft) = 3.34451 m 2.
- Square yard; 1 yd 2 (sq yd) = 0.836127 m 2 .
Sq (square) - square.
The unit of measurement in SI is m 3.
- Cubic foot; 1 ft 3 (also cu ft) = 28.3169 dm 3.
- Cubic veil; 1 fath 3 (fth 3; Ft 3; cu Ft) = 6.11644 m 3.
- Cubic yard; 1 yd 3 (cu yd) = 0.764555 m 3.
- Cubic inch; 1 in 3 (cu in) = 16.3871 cm 3.
- Bushel (UK); 1 bu (uk, also UK) = 36.3687 dm 3.
- Bushel (USA); 1 bu (us, also US) = 35.2391 dm 3.
- Gallon (UK); 1 gal (uk, also UK) = 4.54609 dm 3.
- Liquid Gallon (US); 1 gal (us, also US) = 3.78541 dm 3.
- Gallon dry (US); 1 gal dry (us, also US) = 4.40488 dm 3.
- Jill (gill); 1 gi = 0.12 L (US), 0.14 L (UK).
- Barrel (USA); 1bbl = 0.16 m 3.
UK - United Kingdom - United Kingdom (Great Britain); US - United Stats (USA).
Specific volume
The unit of measurement in SI is m 3 / kg.
- Ft 3 / lb; 1 ft3 / lb = 62.428 dm 3 / kg .
The SI unit is kg.
- Pound (trading) (English libra, pound - weighing, pound); 1 lb = 453.592 g; lbs - pounds. In the system of old Russian measures 1 lb = 409.512 g.
- Gran (English grain - grain, grain, grain); 1 gr = 64.799 mg.
- Stone (English stone - stone); 1 st = 14 lb = 6,350 kg.
Density, incl. bulk
The SI unit is kg / m 3.
- Lb / ft 3; 1 lb / ft 3 = 16.0185 kg / m 3.
Linear density
The SI unit is kg / m.
- Lb / ft; 1 lb / ft = 1.48816 kg / m
- Lb / yard; 1 lb / yd = 0.496055 kg / m
Surface density
The unit of measurement in SI is kg / m 2.
- Lb / ft 2; 1 lb / ft 2 (also lb / sq ft - pound per square foot) = 4.88249 kg / m 2.
Linear Velocity
The SI unit is m / s.
- Ft / h; 1 ft / h = 0.3048 m / h.
- Ft / s; 1 ft / s = 0.3048 m / s.
The SI unit is m / s 2.
- Ft / s 2; 1 ft / s 2 = 0.3048 m / s 2.
Mass flow
The SI unit is kg / s.
- Lb / h; 1 lb / h = 0.453592 kg / h.
- Lb / s; 1 lb / s = 0.453592 kg / s.
Volume flow
The unit of measurement in SI is m 3 / s.
- Ft 3 / min; 1 ft 3 / min = 28.3168 dm 3 / min.
- Yard 3 / min; 1 yd 3 / min = 0.764555 dm 3 / min.
- Gallon / min; 1 gal / min (also GPM - gallon per min) = 3.78541 dm 3 / min.
Specific volumetric flow
- GPM / (sq ft) - gallon (G) per (P) minute (M) / (square (sq) foot (ft)) - gallon per minute per square foot;
1 GPM / (sq ft) = 2445 l / (m 2 h) 1 l / (m 2 h) = 10 -3 m / h. - gpd - gallons per day - gallons per day (day); 1 gpd = 0.1577 dm 3 / h.
- gpm - gallons per minute - gallons per minute; 1 gpm = 0.0026 dm 3 / min.
- gps - gallons per second - gallons per second; 1 gps = 438 10 -6 dm 3 / s.
Sorbate consumption (for example, Cl 2) when filtering through a sorbent layer (for example, active carbon)
- Gals / cu ft (gal / ft 3) - gallons / cubic foot (gallons per cubic foot); 1 Gals / cu ft = 0.13365 dm 3 per 1 dm 3 sorbent.
The unit of measurement in SI is N.
- Pound force; 1 lbf - 4.44822 N. (Analog of the name of the unit of measurement: kilogram-force, kgf. 1 kgf = = 9.80665 N (exactly). 1 lbf = 0.453592 (kg) 9.80665 N = = 4 , 44822 N · 1H = 1 kg · m / s 2
- Poundal (English: poundal); 1 pdl = 0.138255 N. (Poundal is the force imparting an acceleration of 1 ft / s 2 to a mass of one pound, lb ft / s 2.)
Specific gravity
The unit of measurement in SI is N / m 3.
- Lbf / ft 3; 1 lbf / ft 3 = 157.087 N / m 3.
- Poundal / ft 3; 1 pdl / ft 3 = 4.87985 N / m 3.
SI unit - Pa, multiples of units: MPa, kPa.
Specialists in their work continue to use outdated, canceled or previously optionally allowed pressure units: kgf / cm 2; bar; atm... (physical atmosphere); at(technical atmosphere); ata; ati; m water. Art .; mmHg st; torr.
The concepts are used: "absolute pressure", "excess pressure". There are errors when converting some units of pressure measurement in Pa and in its multiples. It should be borne in mind that 1 kgf / cm 2 is equal to 98066.5 Pa (exactly), that is, for small (up to about 14 kgf / cm 2) pressures with sufficient accuracy for work, you can take: 1 Pa = 1 kg / (m · s 2) = 1 N / m 2. 1 kgf / cm 2 ≈ 105 Pa = 0.1 MPa... But already at medium and high pressures: 24 kgf / cm 2 ≈ 23.5 105 Pa = 2.35 MPa; 40 kgf / cm 2 ≈ 39 105 Pa = 3.9 MPa; 100 kgf / cm 2 ≈ 98 105 Pa = 9.8 MPa etc.
Ratios:
- 1 atm (physical) ≈ 101325 Pa ≈ 1.013 105 Pa ≈ 0.1 MPa.
- 1 at (technical) = 1 kgf / cm 2 = 980066.5 Pa ≈ 105 Pa ≈ 0.09806 MPa ≈ 0.1 MPa.
- 0.1 MPa ≈ 760 mm Hg Art. ≈ 10 m H2O Art. ≈ 1 bar.
- 1 Torr (torr, tor) = 1 mm Hg. Art.
- Lbf / in 2; 1 lbf / in 2 = 6.89476 kPa (see below: PSI).
- Lbf / ft 2; 1 lbf / ft 2 = 47.8803 Pa.
- Lbf / yard 2; 1 lbf / yd 2 = 5.32003 Pa.
- Poundal / ft 2; 1 pdl / ft 2 = 1.48816 Pa.
- Foot of water; 1 ft H 2 O = 2.98907 kPa.
- Inch of water; 1 in H 2 O = 249.089 Pa.
- Inch of mercury; 1 in Hg = 3.38639 kPa.
- PSI (also psi) - pounds (P) per square (S) inch (I) - pounds per square inch; 1 PSI = 1 lbƒ / in 2 = 6.89476 kPa.
Sometimes in the literature there is a designation for the unit of measurement of pressure lb / in 2 - this unit does not take into account lbƒ (lbf), but lb (lb-mass). Therefore, in numerical terms, 1 lb / in 2 slightly differs from 1 lbf / in 2, since when determining 1 lbƒ, the following was taken into account: g = 9.80665 m / s 2 (at the latitude of London). 1 lb / in 2 = 0.454592 kg / (2.54 cm) 2 = 0.07046 kg / cm 2 = 7.046 kPa. Calculation of 1 lbƒ - see above. 1 lbf / in 2 = 4.44822 N / (2.54 cm) 2 = 4.44822 kg m / (2.54 0.01 m) 2 s 2 = 6894.754 kg / (m s 2) = 6894.754 Pa ≈ 6.895 kPa.
For practical calculations, you can take: 1 lbf / in 2 ≈ 1 lb / in 2 ≈ 7 kPa. But, in fact, equality is illegal, as well as 1 lbƒ = 1 lb, 1 kgf = 1 kg. PSIg (psig) - the same as PSI, but indicates overpressure; PSIa (psia) - the same as PSI, but emphasizes: absolute pressure; a - absolute, g - gauge (measure, size).
Water pressure
The unit of measurement in SI is m.
- Head in feet (feet-head); 1 ft hd = 0.3048 m
Pressure loss during filtration
- PSI / ft - pounds (P) per square (S) inch (I) / foot (ft) - pounds per square inch / foot; 1 PSI / ft = 22.62 kPa per 1 m of filter bed.
The SI unit is Joule(named after the English physicist J.P. Joule).
- 1 J - mechanical work of a force of 1 N when moving a body at a distance of 1 m.
- Newton (N) is the SI unit of force and weight; 1 N is equal to the force imparting an acceleration of 1 m 2 / s to a body with a mass of 1 kg in the direction of the action of the force. 1 J = 1 Nm.
Heat engineering continues to use the canceled unit for measuring the amount of heat - calorie (cal, cal).
- 1 J (J) = 0.23885 cal. 1 kJ = 0.2388 kcal.
- 1 lbf ft (lbf ft) = 1.35582 J.
- 1 pdl ft (poundal foot) = 42.1401 mJ.
- 1 Btu (British heat unit) = 1.05506 kJ (1 kJ = 0.2388 kcal).
- 1 Therm = 1 · 10 -5 Btu.
POWER, HEAT FLOW |
The SI unit is Watt (W)- by the name of the English inventor J. Watt - mechanical power, at which a work of 1 J is performed in 1 s, or a heat flux equivalent to a mechanical power of 1 W.
- 1 W (W) = 1 J / s = 0.859985 kcal / h (kcal / h).
- 1 lbf ft / s (lbf ft / s) = 1.33582 W.
- 1 lbf ft / min (lbf ft / min) = 22.597 mW.
- 1 lbf ft / h (lbf ft / h) = 376.616 μW.
- 1 pdl ft / s (poundal foot / s) = 42.1401 mW.
- 1 hp (British horsepower / s) = 745.7 W.
- 1 Btu / s (British Heat / s) = 1055.06 W.
- 1 Btu / h (British Heat / hr) = 0.293067 W.
Surface heat flux density
The SI unit is W / m 2.
- 1 W / m 2 (W / m 2) = 0.859985 kcal / (m 2 h) (kcal / (m 2 h)).
- 1 Btu / (ft 2 h) = 2.69 kcal / (m 2 h) = 3.1546 kW / m 2.
Dynamic viscosity (viscosity index), η.
Measurement unit in SI - Pa s. 1 Pa s = 1 N s / m 2;
off-system unit - poise (P). 1 P = 1 dyn s / m 2 = 0.1 Pa s.
- Dina (dyn) - (from the Greek. Dynamic - strength). 1 dyn = 10 -5 N = 1 g · cm / s 2 = 1.02 · 10 -6 kgf.
- 1 lbf h / ft 2 (lbf h / ft 2) = 172.369 kPa s.
- 1 lbf s / ft 2 (lbf s / ft 2) = 47.8803 Pa s.
- 1 pdl s / ft 2 (poundal s / ft 2) = 1.48816 Pa s.
- 1 slug / (ft s) (slug / (ft s)) = 47.8803 Pa s. Slug (slug) - technical unit of mass in the English system of measures.
Kinematic viscosity, ν.
Measurement unit in SI - m 2 / s; The unit cm 2 / s is called "Stokes" (named after the English physicist and mathematician J. G. Stokes).
Kinematic and dynamic viscosities are related by the equality: ν = η / ρ, where ρ is the density, g / cm 3.
- 1 m 2 / s = Stokes / 104.
- 1 ft 2 / h (ft 2 / h) = 25.8064 mm 2 / s.
- 1 ft 2 / s (ft 2 / s) = 929.030 cm 2 / s.
The unit of magnetic field strength in SI is A / m(Ammeter). Ampere (A) - the surname of the French physicist A.M. Ampere.
Previously, the unit Oersted (E) was used - named after the Danish physicist H.K. Oersted.
1 A / m (A / m, At / m) = 0.0125663 Oe (Oe)
The crushing and abrasion resistance of mineral filter materials and, in general, all minerals and rocks is indirectly determined by the Mohs scale (F. Moos is a German mineralogist).
In this scale, numbers in ascending order denote minerals arranged in such a way that each subsequent one is able to leave a scratch on the previous one. The extreme substances on the Mohs scale are talc (the unit of hardness is 1, the softest) and diamond (10, the hardest).
- Hardness 1-2.5 (drawn with a fingernail): volskonkoite, vermiculite, halite, gypsum, glauconite, graphite, clay materials, pyrolusite, talc, etc.
- Hardness> 2.5-4.5 (not drawn with a fingernail, but drawn with glass): anhydrite, aragonite, barite, glauconite, dolomite, calcite, magnesite, muscovite, siderite, chalcopyrite, chabazite, etc.
- Hardness> 4.5-5.5 (not drawn with glass, but drawn with a steel knife): apatite, vernadite, nepheline, pyrolusite, chabazite, etc.
- Hardness> 5.5-7.0 (not drawn with a steel knife, but drawn with quartz): vernadite, garnet, ilmenite, magnetite, pyrite, feldspars, etc.
- Hardness> 7.0 (not drawn with quartz): diamond, garnets, corundum, etc.
The hardness of minerals and rocks can also be determined using the Knoop scale (A. Knoop is a German mineralogist). In this scale, the values are determined by the size of the indentation left on the mineral when a diamond pyramid is pressed into its sample under a certain load.
The ratios of indicators on the Mohs (M) and Knoop (K) scales:
Measurement unit in SI - Bq(Becquerel, named after the French physicist A.A. Becquerel).
Bq (Bq) is the unit of activity of a nuclide in a radioactive source (isotope activity). 1 Bq is equal to the activity of a nuclide, at which one decay occurs in 1 s.
Concentration of radioactivity: Bq / m 3 or Bq / l.
Activity is the number of radioactive decays per unit of time. The activity per unit mass is called specific.
- Curie (Ku, Ci, Cu) is the unit of activity of a nuclide in a radioactive source (isotope activity). 1 Ku is the activity of an isotope in which 3.7000 1010 decay events occur in 1 s. 1 Ku = 3.7000 1010 Bq.
- Rutherford (Rd, Rd) is an obsolete unit of activity of nuclides (isotopes) in radioactive sources, named after the English physicist E. Rutherford. 1 Rd = 1 106 Bq = 1/37000 Ci.
Radiation dose
Radiation dose - the energy of ionizing radiation absorbed by the irradiated substance and calculated per unit of its mass (absorbed dose). The dose builds up over time. Dose rate ≡ Dose / time.
Absorbed dose unit in SI - Gray (Gy, Gy)... The off-system unit is Rad (rad), corresponding to a radiation energy of 100 erg absorbed by a substance with a mass of 1 g.
Erg (erg - from the Greek: ergon - work) is a unit of work and energy in the non-recommended CGS system.
- 1 erg = 10 -7 J = 1.02 · 10 -8 kgf · m = 2.39 · 10 -8 cal = 2.78 · 10 -14 kW · h.
- 1 rad (rad) = 10 -2 Gr.
- 1 rad (rad) = 100 erg / g = 0.01 Gy = 2.388 · 10 -6 cal / g = 10 -2 J / kg.
Kerma (abbreviated English: kinetic energy released in matter) is the kinetic energy released in matter, measured in grays.
The equivalent dose is determined by comparing the emission of nuclides with X-ray radiation. The radiation quality factor (K) shows how many times the radiation hazard in the case of chronic exposure of a person (in relatively small doses) for a given type of radiation is greater than in the case of X-ray radiation with the same absorbed dose. For X-ray and γ-radiation, K = 1. For all other types of radiation, K is established from radiobiological data.
Dekv = DpoglK.
Absorbed dose unit in SI - 1 Sv(Sievert) = 1 J / kg = 102 rem.
- RER (rem, ri - until 1963 was defined as the biological equivalent of an X-ray) is a unit of an equivalent dose of ionizing radiation.
- Roentgen (P, R) - unit of measurement, exposure dose of X-ray and γ-radiation. 1 Р = 2.58 · 10 -4 C / kg.
- Pendant (Kl) - a unit in the SI system, the amount of electricity, electric charge. 1 rem = 0.01 J / kg.
Equivalent dose rate - Sv / s.
Permeability of porous media (including rocks and minerals)
Darcy (D) - named after the French engineer A. Darcy, darsy (D) 1 D = 1.01972 μm 2.
1 D - the permeability of such a porous medium, when filtering through a sample of which an area of 1 cm 2, a thickness of 1 cm and a pressure drop of 0.1 MPa, the flow rate of a liquid with a viscosity of 1 cP is equal to 1 cm 3 / s.
Sizes of particles, grains (granules) of filter materials according to SI and other countries' standards
In the USA, Canada, Great Britain, Japan, France and Germany, the grain sizes are estimated in meshes (eng. Mesh - hole, cell, net), that is, by the number (number) of holes per inch of the smallest sieve through which they can pass grains. And the effective grain diameter is considered to be the hole size in microns. In recent years, the US and UK mesh systems have been used more frequently.
The ratio between the units of measurement of the sizes of grains (granules) of filtering materials according to SI and standards of other countries:
Mass fraction
Mass fraction shows what mass quantity of a substance is contained in 100 mass parts of a solution. Units of measurement: fractions of a unit; percent (%); ppm (‰); parts per million (ppm).
Concentration of solutions and solubility
The concentration of a solution must be distinguished from solubility - the concentration of a saturated solution, which is expressed by the mass amount of a substance in 100 mass parts of a solvent (for example, g / 100 g).
Volume concentration
Volumetric concentration is the mass amount of a solute in a certain volume of solution (for example: mg / l, g / m 3).
Molar concentration
Molar concentration - the number of moles of a given substance, dissolved in a certain volume of solution (mol / m 3, mmol / l, µmol / ml).
Molar concentration
Molar concentration - the number of moles of a substance contained in 1000 g of solvent (mol / kg).
Normal solution
A normal solution is a solution containing one equivalent of a substance per unit volume, expressed in mass units: 1H = 1 mg eq / l = 1 mmol / l (indicating the equivalent of a specific substance).
Equivalent
The equivalent is equal to the ratio of the part of the mass of an element (substance) that adds or replaces one atomic mass of hydrogen or half of the atomic mass of oxygen in a chemical compound to 1/12 of the mass of carbon 12. So, the equivalent of an acid is equal to its molecular weight, expressed in grams, divided by the basicity (the number of hydrogen ions); base equivalent - molecular weight divided by acidity (the number of hydrogen ions, and for inorganic bases - divided by the number of hydroxyl groups); salt equivalent - molecular weight divided by the sum of charges (valence of cations or anions); the equivalent of a compound participating in redox reactions is the quotient of dividing the molecular weight of the compound by the number of electrons taken (donated) by the atom of the reducing (oxidizing) element.
Relationship between units of measurement of concentration of solutions
(Formulas for the transition from one expression of the concentration of solutions to another):
Accepted designations:
- ρ is the density of the solution, g / cm 3;
- m is the molecular weight of the solute, g / mol;
- E is the equivalent mass of a solute, that is, the amount of substance in grams that interacts in a given reaction with one gram of hydrogen or corresponds to the transition of one electron.
According to GOST 8.417-2002 the unit of the amount of the substance is set: mol, multiples and sub-multiples ( kmol, mmol, μmol).
The unit of measurement for hardness in SI is mmol / l; μmol / l.
In different countries, the canceled units for measuring water hardness often continue to be used:
- Russia and the CIS countries - mg-eq / l, mcg-eq / l, g-eq / m 3;
- Germany, Austria, Denmark and some other countries of the Germanic language group - 1 German degree - (H ° - Harte - hardness) ≡ 1 hour CaO / 100 thousand hours of water ≡ 10 mg CaO / l ≡ 7.14 mg MgO / l ≡ 17.9 mg CaCO 3 / l ≡ 28.9 mg Ca (HCO 3) 2 / l ≡ 15.1 mg MgCO 3 / l ≡ 0.357 mmol / l.
- 1 French degree ≡ 1 h. CaCO 3/100 thousand parts of water ≡ 10 mg CaCO 3 / l ≡ 5.2 mg CaO / l ≡ 0.2 mmol / l.
- 1 English degree ≡ 1 grain / 1 gallon of water ≡ 1 h. CaCO 3/70 thousand parts of water ≡ 0.0648 g CaCO 3 / 4.546 l ≡ 100 mg CaCO3 / 7 l ≡ 7.42 mg CaO / l ≡ 0.285 mmol / l. Sometimes the English degree of hardness is referred to as Clark.
- 1 American degree ≡ 1 h. CaCO 3/1 million ppm of water ≡ 1 mg CaCO 3 / l ≡ 0.52 mg CaO / l ≡ 0.02 mmol / l.
Here: ch. - part; the conversion of degrees into the corresponding amounts of CaO, MgO, CaCO 3, Ca (HCO 3) 2, MgCO 3 is shown as examples mainly for German degrees; the dimensions of degrees are tied to calcium-containing compounds, since in the composition of hardness ions calcium, as a rule, is 75-95%, in rare cases - 40-60%. Numbers are generally rounded to the second decimal place.
Relationship between the units for measuring water hardness:
1 mmol / L = 1 mg eq / L = 2.80 ° N (German degree) = 5.00 French degrees = 3.51 English degrees = 50.04 American degrees.
A new unit for measuring water hardness is the Russian degree of hardness - ° F, defined as the concentration of an alkaline earth element (mainly Ca 2+ and Mg 2+), numerically equal to ½ of its mole in mg / dm 3 (g / m 3).
Alkalinity is measured in mmol, μmol.
The unit of measurement for electrical conductivity in SI is μS / cm.
The electrical conductivity of solutions and its inverse electrical resistance characterize the salinity of solutions, but only the presence of ions. When measuring electrical conductivity, nonionic organic substances, neutral suspended impurities, interferences that distort the results, gases, etc. cannot be taken into account. In natural water, different ions have different electrical conductivity, which simultaneously depends on the salinity of the solution and its temperature. To establish such a relationship, it is necessary to experimentally establish the relationship between these values for each specific object several times a year.
- 1 μS / cm = 1 MOm cm; 1 S / m = 1 Ohm m.
For pure solutions of sodium chloride (NaCl) in distillate, the approximate ratio is:
- 1 μS / cm ≈ 0.5 mg NaCl / L.
The same ratio (approximately), taking into account the above reservations, can be adopted for most natural waters with salinity up to 500 mg / l (all salts are recalculated to NaCl).
With the mineralization of natural water 0.8-1.5 g / l, you can take:
- 1 μS / cm ≈ 0.65 mg salts / l,
and with mineralization - 3-5 g / l:
- 1 μS / cm ≈ 0.8 mg salts / l.
Content of suspended impurities in water, transparency and turbidity of water
Turbidity of water is expressed in units:
- JTU (Jackson Turbidity Unit) - Jackson turbidity unit;
- FTU (Formasin Turbidity Unit, also denoted EMF) - formazin turbidity unit;
- NTU (Nephelometric Turbidity Unit) - nephelometric unit of turbidity.
It is impossible to give an exact ratio of units of turbidity and content of suspended solids. For each series of determinations, it is necessary to build a calibration graph that allows you to determine the turbidity of the analyzed water in comparison with the control sample.
It is possible to represent approximately: 1 mg / l (suspended solids) ≡ 1-5 NTU units.
If the turbid mixture (diatomaceous earth) has a particle size of 325 mesh, then: 10 units. NTU ≡ 4 units JTU.
GOST 3351-74 and SanPiN 2.1.4.1074-01 equate to 1.5 units. NTU (or 1.5 mg / L based on silica or kaolin) 2.6 units. FTU (EMF).
The relationship between font transparency and haze:
The ratio between the transparency on the "cross" (in cm) and turbidity (in mg / l):
The SI unit is mg / l, g / m 3, μg / l.
In the United States and in some other countries, mineralization is expressed in relative units (sometimes in grains per gallon, gr / gal):
- ppm (parts per million) - millionth part (1 · 10 -6) unit; sometimes ppm (parts per millе) also denote a thousandth (1 · 10 -3) unit;
- ppb - (parts per billion) billionth (billionth) share (1 · 10 -9) units;
- ppt - (parts per trillion) trillionth (1 · 10 -12) unit;
- ‰ - ppm (also used in Russia) - thousandth (1 · 10 -3) unit.
The ratio between the units of measurement of mineralization: 1mg / l = 1ррm = 1 · 10 3 ррb = 1 · 10 6 ррt = 1 · 10 -3 ‰ = 1 · 10 -4%; 1 gr / gal = 17.1 ppm = 17.1 mg / l = 0.142 lb / 1000 gal.
For measuring salinity of saline waters, brines and salinity of condensates it is more correct to use units: mg / kg... In laboratories, water samples are measured in volumetric rather than mass fractions, therefore, it is advisable in most cases to attribute the amount of impurities to a liter. But for large or very small values of mineralization, the error will be sensitive.
According to SI, the volume is measured in dm 3, but measurement is also allowed in liters, because 1 l = 1.000028 dm 3. Since 1964 1 liter is equivalent to 1 dm 3 (exactly).
For salt water and brines salinity units are sometimes used in Baume degrees(for mineralization> 50 g / kg):
- 1 ° Be corresponds to a solution concentration of 1% in terms of NaCl.
- 1% NaCl = 10 g NaCl / kg.
Dry and calcined residue
Dry and calcined residue are measured in mg / l. The dry residue does not fully characterize the salinity of the solution, since the conditions for its determination (boiling, drying the solid residue in an oven at a temperature of 102-110 ° C to constant weight) distort the result: in particular, part of the bicarbonates (conventionally taken as half) decomposes and volatilizes as CO 2.
Decimal multiples and sub-multiples of measurement units
Decimal multiples and sub-multiples of quantities, as well as their names and designations, should be formed using the multipliers and prefixes given in the table:
(based on materials from the site https://aqua-therm.ru/).
Physics, as a science that studies natural phenomena, uses a standard research methodology. The main stages can be called: observation, hypothesis, experiment, theory substantiation. During the observation, the distinctive features of the phenomenon, the course of its course, possible causes and consequences are established. The hypothesis makes it possible to explain the course of the phenomenon, to establish its laws. The experiment confirms (or does not confirm) the validity of the hypothesis. Allows you to establish a quantitative ratio of values in the course of the experiment, which leads to the precise establishment of dependencies. The hypothesis, confirmed in the course of the experiment, forms the basis of the scientific theory.
No theory can claim to be reliable if it has not received complete and unconditional confirmation during the experiment. Carrying out the latter is associated with measurements of physical quantities characterizing the process. is the basis of measurements.
What it is
Measurement concerns those quantities that confirm the validity of the hypothesis of patterns. A physical quantity is a scientific characteristic of a physical body, the qualitative relation of which is common to many similar bodies. For each body, such a quantitative characteristic is purely individual.
If we turn to the specialized literature, then in the reference book by M. Yudin et al. (1989 edition) we read that a physical quantity is: “a characteristic of one of the properties of a physical object (physical system, phenomenon or process), qualitatively common to many physical objects, but quantitatively individual for each object ”.
Ozhegov's Dictionary (1990 edition) states that a physical quantity is "the size, volume, extension of an object."
For example, length is a physical quantity. Mechanics treats length as the distance traveled, electrodynamics uses the length of the wire, in thermodynamics, a similar value determines the thickness of the walls of the vessels. The essence of the concept does not change: the units of quantities can be the same, but the meaning can be different.
A distinctive feature of a physical quantity, say, from a mathematical one, is the presence of a unit of measurement. Meter, foot, arshin are examples of length units.
Units
To measure a physical quantity, it must be compared with a quantity taken as a unit. Remember the wonderful cartoon "Forty-Eight Parrots". To establish the length of the boa constrictor, the heroes measured its length in parrots, in elephants, in monkeys. In this case, the length of the boa constrictor was compared with the growth of other cartoon characters. The result was quantitatively dependent on the reference.
Quantities are a measure of its measurement in a certain system of units. Confusion in these measures arises not only due to imperfection, heterogeneity of measures, but sometimes also due to the relativity of units.
Russian measure of length - arshin - the distance between the index and thumb. However, the hands of all people are different, and the yardstick measured by the hand of an adult man differs from the yardstick on the hand of a child or woman. The same discrepancy between the measures of length applies to the fathom (the distance between the tips of the fingers spaced to the sides of the hands) and the elbow (the distance from the middle finger to the elbow of the hand).
It is interesting that men of small stature were taken to the shops as clerks. Sly merchants saved fabric with the help of several smaller measures: arshin, elbow, fathom.
Systems of measures
Such a variety of measures existed not only in Russia, but also in other countries. The introduction of units of measurement was often arbitrary, sometimes these units were introduced only because of the convenience of their measurement. For example, mmHg was entered to measure atmospheric pressure. The famous one that used a tube filled with mercury allowed the introduction of such an unusual value.
The power of the engines was compared with (which is still practiced in our time).
Various physical quantities made the measurement of physical quantities not only difficult and unreliable, but also complicating the development of science.
Unified system of measures
A unified system of physical quantities, convenient and optimized in every industrialized country, has become an urgent need. The idea of choosing as few units as possible, with the help of which other quantities could be expressed in mathematical relations, was taken as a basis. Such basic values should not be related to each other, their meaning is determined unambiguously and understandably in any economic system.
Various countries have tried to solve this problem. The creation of a single SGS, ISS and others) was undertaken repeatedly, but these systems were inconvenient either from a scientific point of view, or in domestic, industrial use.
The problem posed at the end of the 19th century was solved only in 1958. A unified system was presented at the meeting of the International Committee of Legal Metrology.
Unified system of measures
1960 saw the historic General Conference on Weights and Measures. A unique system called "Systeme internationale d" unites "(abbreviated SI) was adopted by the decision of this honorary meeting. In the Russian version this system is called the International System (abbreviation SI).
7 basic units and 2 additional ones are taken as a basis. Their numerical value is determined as a standard
SI table of physical quantities
Name of the main unit | Measured value | Designation |
|
International | Russian |
||
Basic units |
|||
kilogram | |||
Current strength | |||
Temperature | |||
Amount of substance | |||
The power of light | |||
Additional units |
|||
Flat angle | |||
Steradian | Solid angle | ||
The system itself cannot consist of only seven units, since the variety of physical processes in nature requires the introduction of more and more new quantities. The structure itself provides not only the introduction of new units, but also their relationship in the form of mathematical ratios (they are more often called dimension formulas).
The unit of a physical quantity is obtained using multiplication and division of the base units in the dimension formula. The absence of numerical coefficients in such equations makes the system not only convenient in all respects, but also coherent (consistent).
Derived units
The units of measurement that are formed from the seven basic ones are called derivatives. In addition to the basic and derived units, it became necessary to introduce additional ones (radians and steradians). Their dimension is considered to be zero. The absence of measuring instruments for their determination makes it impossible to measure them. Their introduction is due to their application in theoretical research. For example, the physical quantity "force" in this system is measured in newtons. Since force is a measure of the mutual action of bodies on each other, which is the reason for varying the speed of a body of a certain mass, it can be defined as the product of a unit of mass per unit of speed, divided by a unit of time:
F = k٠M٠v / T, where k is the coefficient of proportionality, M is the unit of mass, v is the unit of speed, T is the unit of time.
SI gives the following dimension formula: H = kg٠m / s 2, where three units are used. And the kilogram, and the meter, and the second are classified as basic. The aspect ratio is 1.
It is possible to introduce dimensionless quantities, which are determined as a ratio of homogeneous quantities. These include, as is known, equal to the ratio of the friction force to the force of normal pressure.
Table of physical quantities derived from basic
Unit name | Measured value | Dimension formula |
kg٠m 2 ٠s -2 |
||
pressure | kg٠ m -1 ٠s -2 |
|
magnetic induction | kg ٠A -1 ٠s -2 |
|
electrical voltage | kg ٠m 2 ٠s -3 ٠А -1 |
|
Electrical resistance | kg ٠m 2 ٠s -3 ٠А -2 |
|
Electric charge | ||
power | kg ٠m 2 ٠s -3 |
|
Electrical capacity | m -2 ٠kg -1 ٠s 4 ٠A 2 |
|
Joule to Kelvin | Heat capacity | kg ٠m 2 ٠s -2 ٠K -1 |
Becquerel | Activity of a radioactive substance | |
Magnetic flux | m 2 ٠kg ٠s -2 ٠А -1 |
|
Inductance | m 2 ٠kg ٠s -2 ٠А -2 |
|
Absorbed dose | ||
Equivalent dose of radiation | ||
Illumination | m -2 ٠cd ٠sr -2 |
|
Light flow | ||
Strength, weight | m ٠kg ٠s -2 |
|
Electrical conductivity | m -2 ٠kg -1 ٠s 3 ٠А 2 |
|
Electrical capacity | m -2 ٠kg -1 ٠s 4 ٠A 2 |
Non-system units
The use of historically established quantities that are not included in the SI or differ only in a numerical coefficient is allowed when measuring quantities. These are non-systemic units. For example, mm Hg, X-rays and others.
Numeric coefficients are used to enter sub-multiples and multiples. The prefixes correspond to a specific number. Examples include centi, kilo, deca, mega, and many others.
1 kilometer = 1000 meters,
1 centimeter = 0.01 meter.
Typology of quantities
Let's try to indicate a few basic features that allow us to establish the type of value.
1. Direction. If the action of a physical quantity is directly related to the direction, it is called vector, others are scalar.
2. Availability of dimension. The existence of a formula for physical quantities makes it possible to call them dimensional. If in the formula all units have degree zero, then they are called dimensionless. It would be more correct to call them quantities with a dimension equal to 1. After all, the concept of a dimensionless quantity is illogical. The main property - dimension - has not been canceled!
3. If possible, addition. An additive quantity, the value of which can be added, subtracted, multiplied by a coefficient, etc. (for example, mass) is a physical quantity that is summable.
4. In relation to the physical system. Extensive - if its value can be composed from the values of the subsystem. An example is the area measured in square meters. Intensive - a value, the value of which does not depend on the system. These include temperature.
This tutorial will not be new to beginners. We have all heard such things from school as centimeter, meter, kilometer. And when it came to mass, they usually said gram, kilogram, ton.
Centimeters, meters and kilometers; grams, kilograms and tons have one common name - units of measurement of physical quantities.
In this lesson, we will look at the most popular units of measurement, but we will not go deep into this topic, since units of measurement go into the field of physics. Today we are forced to study a part of physics, since we need it for further study of mathematics.
Lesson contentLength units
The following units of measure are intended for measuring length:
- millimeters;
- centimeters;
- decimeters;
- meters;
- kilometers.
millimeter(mm). You can even see millimeters with your own eyes if you take the ruler that we used at school every day.
Consecutive small lines running one after another are millimeters. More precisely, the distance between these lines is equal to one millimeter (1 mm):
centimeter(cm). On the ruler, each centimeter is marked with a number. For example, our ruler, which was in the first picture, had a length of 15 centimeters. The last centimeter on this ruler is marked with the number 15.
There are 10 millimeters in one centimeter. An equal sign can be placed between one centimeter and ten millimeters, since they represent the same length:
1 cm = 10 mm
You can see for yourself if you count the number of millimeters in the previous figure. You will find that the number of millimeters (distance between lines) is 10.
The next unit of measure for length is decimeter(dm). There are ten centimeters in one decimeter. An equal sign can be placed between one decimeter and ten centimeters, since they denote the same length:
1 dm = 10 cm
You can verify this if you count the number of centimeters in the following figure:
You will find that the number of centimeters is 10.
The next unit of measurement is meter(m). There are ten decimeters in one meter. An equal sign can be put between one meter and ten decimeters, since they denote the same length:
1 m = 10 dm
Unfortunately, the meter cannot be illustrated in the figure because it is quite large. If you want to see the meter live, take a tape measure. Everyone in the house has it. On a tape measure, one meter will be designated as 100 cm.This is because there are ten decimeters in one meter, and one hundred centimeters in ten decimeters:
1 m = 10 dm = 100 cm
100 is obtained by converting one meter to centimeters. This is a separate topic, which we will consider a little later. In the meantime, let's move on to the next unit of measure for length, which is called a kilometer.
The kilometer is considered the largest unit of measure for length. There are, of course, other older units, such as megameter, gigameter, terameter, but we will not consider them, since a kilometer is enough for us to study mathematics further.
One kilometer is a thousand meters. An equal sign can be placed between one kilometer and one thousand meters, since they represent the same length:
1 km = 1000 m
Distances between cities and countries are measured in kilometers. For example, the distance from Moscow to St. Petersburg is about 714 kilometers.
International system of units SI
The international system of units SI is a certain set of generally accepted physical quantities.
The main purpose of the international system of SI units is to achieve agreements between countries.
We know that the languages and traditions of the countries of the world are different. There is nothing you can do about it. But the laws of mathematics and physics work the same everywhere. If in one country “twice two will be four”, then in another country “twice two will be four”.
The main problem was that there are several units of measurement for each physical quantity. For example, we have now learned that there are millimeters, centimeters, decimeters, meters and kilometers for measuring length. If several scientists speaking different languages gather in one place to solve a problem, then such a large variety of units of measurement of length can give rise to contradictions between these scientists.
One scientist will state that in their country, length is measured in meters. The second might say that in their country, length is measured in kilometers. The third can offer its own unit of measurement.
Therefore, the international system of units SI was created. SI is an abbreviation for the French phrase. Le Système International d'Unités, SI (which translated into Russian means - the international system of units SI).
The SI contains the most popular physical quantities and each of them has its own generally accepted unit of measurement. For example, in all countries, when solving problems, it was agreed that the length would be measured in meters. Therefore, when solving problems, if the length is given in another unit of measurement (for example, in kilometers), then it must be converted to meters. We will talk about how to convert one unit of measurement to another a little later. In the meantime, let's draw our international system of units, SI.
Our figure will be a table of physical quantities. We will include each studied physical quantity in our table and indicate the unit of measurement that is accepted in all countries. Now we have studied the units of measurement of length and learned that in the SI system, meters are defined for measuring length. So our table will look like this:
Mass units
Mass is a quantity that indicates the amount of a substance in a body. In the people, body weight is called weight. Usually, when something is weighed, they say "It weighs so many kilograms" , although we are not talking about weight, but about the mass of this body.
However, mass and weight are different concepts. Weight is the force with which a body acts on a horizontal support. Weight is measured in Newtons. And mass is a quantity that shows the amount of matter in this body.
But there is nothing wrong if you call body weight weight. Even in medicine they say "Human weight" , although we are talking about the mass of a person. The main thing is to be aware that these are different concepts.
The following units are used to measure mass:
- milligrams;
- grams;
- kilograms;
- centners;
- tons.
The smallest unit of measurement is milligram(mg). You will most likely never use a milligram in practice. They are used by chemists and other scientists who work with fine substances. It is enough for you to know that such a unit of measure for mass exists.
The next unit of measurement is gram(G). In grams, it is customary to measure the amount of a product when drawing up a recipe.
There are a thousand milligrams in one gram. An equal sign can be placed between one gram and a thousand milligrams, since they denote the same mass:
1 g = 1000 mg
The next unit of measurement is kilogram(kg). The kilogram is a common unit of measurement. Anything is measured in it. The kilogram is included in the SI system. Let's and we will include one more physical quantity in our SI table. We will call it "mass":
One kilogram contains a thousand grams. An equal sign can be placed between one kilogram and one thousand grams, since they denote the same mass:
1 kg = 1000 g
The next unit of measurement is centner(c). In centners, it is convenient to measure the mass of the crop harvested from a small area or the mass of some kind of cargo.
One centner contains one hundred kilograms. You can put an equal sign between one centner and one hundred kilograms, since they denote the same mass:
1 q = 100 kg
The next unit of measurement is ton(T). Large loads and masses of large bodies are usually measured in tons. For example, the mass of a spaceship or car.
There are a thousand kilograms in one ton. An equal sign can be put between one ton and a thousand kilograms, since they denote the same mass:
1 t = 1000 kg
Time units
We do not need to explain what time is. Everyone knows what time is and why it is needed. If we open a discussion on what time is and try to define it, then we will begin to delve into philosophy, and we do not need this now. Let's start with the units of time.
The following units of measure are used to measure time:
- seconds;
- minutes;
- watch;
- day.
The smallest unit of measurement is second(with). There are, of course, smaller units such as milliseconds, microseconds, nanoseconds, but we will not consider them, since at the moment there is no point in this.
Various indicators are measured in seconds. For example, in how many seconds an athlete will run 100 meters. The second is included in the SI international system of units for measuring time and is denoted as "s". Let's and we will include one more physical quantity in our SI table. We will call it "time":
minute(m). One minute 60 seconds. An equal sign can be placed between one minute and sixty seconds, since they represent the same time:
1 m = 60 s
The next unit of measurement is hour(h). One hour 60 minutes. An equal sign can be placed between one hour and sixty minutes, since they represent the same time:
1 h = 60 m
For example, if we studied this lesson for one hour and we are asked how much time we spent studying it, we can answer in two ways: "We studied the lesson for one hour" or so "We studied the lesson for sixty minutes" ... In both cases, we will answer correctly.
The next time unit is day... There are 24 hours a day. Between one day and twenty-four hours, you can put an equal sign, since they denote the same time:
1 day = 24 hours
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STATE SUPPORT SYSTEM
UNITS OF MEASUREMENT
UNITS OF PHYSICAL QUANTITIES
GOST 8.417-81
(ST SEV 1052-78)
USSR STATE COMMITTEE ON STANDARDS
Moscow
DEVELOPED USSR State Committee for Standards CONTRACTORSYu.V. Tarbeev, Dr. Tech. sciences; K.P. Shirokov, Dr. Tech. sciences; P.N. Selivanov, Cand. tech. sciences; ON. EryukhinaINTRODUCED USSR State Committee for Standards Member of Gosstandart OK. IsaevAPPROVED AND COMMITTED INTO ACTION Resolution of the USSR State Committee for Standards dated March 19, 1981 No. 1449STATE STANDARD OF THE UNION OF SSR
|
State system for ensuring the uniformity of measurements UNITSPHYSICALVELICHIN State system for ensuring the uniformity of measurements. Units of physical quantities |
GOST 8.417-81 (ST SEV 1052-78) |
from 01.01 1982
This standard establishes units of physical quantities (hereinafter referred to as units) used in the USSR, their names, designations and rules for the use of these units.The standard does not apply to units used in scientific research and when publishing their results, if they do not consider and use the results measurements of specific physical quantities, as well as units of quantities, assessed according to conventional scales *. * Conventional scales mean, for example, Rockwell and Vickers hardness scales, photosensitivity of photographic materials. The standard corresponds to ST SEV 1052-78 in terms of general provisions, units of the International System, units that are not part of the SI, rules for the formation of decimal multiples and sub-multiples, as well as their names and designations, rules for writing unit designations, rules for the formation of coherent derived SI units ( see reference annex 4).
1. GENERAL PROVISIONS
1.1. Units of the International System of Units *, as well as decimal multiples and sub-multiples of them are subject to mandatory use (see Section 2 of this standard). * International system of units (international abbreviated name - SI, in Russian transcription - SI), adopted in 1960 by the XI General Conference on Weights and Measures (GCMW) and refined at subsequent GCMV. 1.2. It is allowed to use on a par with the units of clause 1.1, units that are not included in the SI, in accordance with clauses. 3.1 and 3.2, their combinations with SI units, as well as some decimal multiples and sub-multiples of the above units that have found wide application in practice. 1.3. It is temporarily allowed to use, along with the units of clause 1.1, units that are not included in the SI, in accordance with clause 3.3, as well as some that have become widespread in practice in multiples and sub-multiples of them, combinations of these units with SI units, decimal multiples and sub-multiples of them and with units according to clause 3.1. 1.4. In newly developed or revised documentation, as well as publications, the values of quantities should be expressed in SI units, decimal multiples and sub-multiples of them and (or) in units allowed for use in accordance with clause 1.2. It is also allowed in the specified documentation to use units according to clause 3.3, the expiration date of which will be established in accordance with international agreements. 1.5. The newly approved normative and technical documentation for measuring instruments should provide for their calibration in SI units, decimal multiples and sub-multiples of them, or in units allowed for use in accordance with clause 1.2. 1.6. The newly developed normative and technical documentation on methods and means of verification should provide for the verification of measuring instruments, calibrated in newly introduced units. 1.7. The SI units established by this standard and the units allowed for use in clauses 3.1 and 3.2, should be applied in the educational processes of all educational institutions, in textbooks and teaching aids. 1.8. Revision of the regulatory, technical, design, technological and other technical documentation, in which units are used that are not provided for in this standard, as well as bringing them into compliance with paragraphs. 1.1 and 1.2 of this standard, measuring instruments calibrated in units to be withdrawn are carried out in accordance with clause 3.4 of this standard. 1.9. In contractual and legal relations on cooperation with foreign countries, with participation in the activities of international organizations, as well as in technical and other documentation supplied abroad together with export products (including transport and consumer packaging), international designations of units are used. In the documentation for export products, if this documentation is not sent abroad, it is allowed to use Russian designations of units. (New edition, Amendment No. 1). 1.10. In the normative and technical design, technological and other technical documentation for various types of products and products used only in the USSR, preferably Russian designations of units are used. At the same time, regardless of which designations of units are used in the documentation for measuring instruments, when specifying units of physical quantities on the plates, scales and shields of these measuring instruments, international designations of units are used. (New edition, Amendment No. 2). 1.11. In printed publications, it is allowed to use either international or Russian designations of units. Simultaneous use of both types of designations in the same edition is not allowed, with the exception of publications on units of physical quantities.2. UNITS OF THE INTERNATIONAL SYSTEM
2.1. The basic SI units are given in table. 1.Table 1
|
The magnitude |
|||||
|
Name |
Dimension |
Name |
Designation |
Definition |
|
|
international |
|||||
| Length | The meter is the length of the path traversed by light in a vacuum during the time interval 1/299792458 S [XVII CGPM (1983), Resolution 1]. | ||||
| Weight |
kilogram |
A kilogram is a unit of mass equal to the mass of the international prototype of the kilogram [I GKMV (1889) and III GKMV (1901)] | |||
| Time | A second is a time equal to 9192631770 periods of radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom [XIII GCMW (1967), Resolution 1] | ||||
| Electric current strength | An ampere is a force equal to the strength of a constant current, which, when passing through two parallel rectilinear conductors of infinite length and negligible circular cross-sectional area, located in a vacuum at a distance of 1 m from one another, would cause an interaction force equal to 2 × 10 -7 N [CIPM (1946), Resolution 2, approved by the IX CGPM (1948)] | ||||
| Thermodynamic temperature | Kelvin is a unit of thermodynamic temperature equal to 1 / 273.16 of the thermodynamic temperature of the triple point of water [X III GCMW (1967), Resolution 4] | ||||
| Amount of substance | A mole is the amount of matter in a system containing as many structural elements as there are atoms in carbon-12 weighing 0.012 kg. When using a mole, the structural elements must be specified and can be atoms, molecules, ions, electrons and other particles or specified groups of particles [XIV CMPP (1971), Resolution 3] | ||||
| The power of light | Candela is the force equal to the luminous intensity in a given direction of a source emitting monochromatic radiation with a frequency of 540 × 10 12 Hz, the luminous intensity of which in this direction is 1/683 W / sr [XVI CGMW (1979), Resolution 3] | ||||
| Notes: 1. In addition to the Kelvin temperature (designation T) it is also allowed to use the Celsius temperature (designation t) defined by the expression t = T - T 0, where T 0 = 273.15 K by definition. Kelvin temperature is expressed in Kelvin, Celsius temperature - in Celsius (international and Russian designation ° С). A degree Celsius is equal in size to a Kelvin. 2. The interval or temperature difference Kelvin is expressed in Kelvin. The interval or difference in Celsius temperatures can be expressed in both Kelvin and Celsius degrees. 3. The designation of the International Practical Temperature in the International Practical Temperature Scale of 1968, if it is necessary to distinguish it from the thermodynamic temperature, is formed by adding the index "68" to the designation of the thermodynamic temperature (for example, T 68 or t 68). 4. The unity of light measurements is ensured in accordance with GOST 8.023-83. | |||||
table 2
|
Name of quantity |
||||
|
Name |
Designation |
Definition |
||
|
international |
||||
| Flat angle | Radian is the angle between two radii of a circle, the length of the arc between which is equal to the radius | |||
| Solid angle |
steradian |
The steradian is a solid angle with a vertex in the center of the sphere, cutting out on the surface of the sphere an area equal to the area of a square with a side equal to the radius of the sphere | ||
Table 3
Examples of SI derived units, the names of which are formed from the names of basic and additional units
|
The magnitude |
||||
|
Name |
Dimension |
Name |
Designation |
|
|
international |
||||
| Square |
square meter |
|||
| Volume, capacity |
cubic meter |
|||
| Speed |
meter per second |
|||
| Angular velocity |
radians per second |
|||
| Acceleration |
meter per square second |
|||
| Angular acceleration |
radian per second squared |
|||
| Wave number |
meter minus the first degree |
|||
| Density |
kilogram per cubic meter |
|||
| Specific volume |
cubic meter per kilogram |
|||
|
ampere per square meter |
||||
|
ampere per meter |
||||
| Molar concentration |
mole per cubic meter |
|||
| Ionizing particle flux |
second to minus first power |
|||
| Particle flux density |
second to minus first degree - meter to minus second degree |
|||
| Brightness |
candela per square meter |
|||
Table 4
SI derived units with special names
|
The magnitude |
|||||
|
Name |
Dimension |
Name |
Designation |
Expression in terms of basic and additional, SI units |
|
|
international |
|||||
| Frequency | |||||
| Strength, weight | |||||
| Pressure, mechanical stress, elastic modulus | |||||
| Energy, work, amount of heat |
m 2 × kg × s -2 |
||||
| Power, energy flow |
m 2 × kg × s -3 |
||||
| Electric charge (amount of electricity) | |||||
| Electric voltage, electric potential, electric potential difference, electromotive force |
m 2 × kg × s -3 × A -1 |
||||
| Electrical capacity |
L -2 M -1 T 4 I 2 |
m -2 × kg -1 × s 4 × A 2 |
|||
|
m 2 × kg × s -3 × A -2 |
|||||
| Electrical conductivity |
L -2 M -1 T 3 I 2 |
m -2 × kg -1 × s 3 × A 2 |
|||
| Magnetic induction flux, magnetic flux |
m 2 × kg × s -2 × A -1 |
||||
| Magnetic flux density, magnetic induction |
kg × s -2 × A -1 |
||||
| Inductance, mutual inductance |
m 2 × kg × s -2 × A -2 |
||||
| Light flow | |||||
| Illumination |
m -2 × cd × sr |
||||
| Nuclide activity in a radioactive source (radionuclide activity) |
becquerel |
||||
| Absorbed dose of radiation, kerma, absorbed dose index (absorbed dose of ionizing radiation) | |||||
| Equivalent dose of radiation | |||||
Table 5
Examples of SI derived units, the names of which are formed using the special names given in table. 4
|
The magnitude |
|||||
|
Name |
Dimension |
Name |
Designation |
Expression in terms of basic and additional SI units |
|
|
international |
|||||
| Moment of power |
newton meter |
m 2 × kg × s -2 |
|||
| Surface tension |
Newton per meter |
||||
| Dynamic viscosity |
pascal second |
m -1 × kg × s -1 |
|||
|
pendant per cubic meter |
|||||
| Electrical displacement |
pendant per square meter |
||||
|
volts per meter |
m × kg × s -3 × A -1 |
||||
| Absolute dielectric constant |
L -3 M -1 × T 4 I 2 |
farad per meter |
m -3 × kg -1 × s 4 × A 2 |
||
| Absolute magnetic permeability |
henry per meter |
m × kg × s -2 × A -2 |
|||
| Specific energy |
joule per kilogram |
||||
| Heat capacity of the system, entropy of the system |
joule per kelvin |
m 2 × kg × s -2 × K -1 |
|||
| Specific heat, specific entropy |
joule per kilogram-kelvin |
J / (kg × K) |
m 2 × s -2 × K -1 |
||
| Surface energy flux density |
watt per square meter |
||||
| Thermal conductivity |
watt per meter-kelvin |
m × kg × s -3 × K -1 |
|||
|
joule per mole |
m 2 × kg × s -2 × mol -1 |
||||
| Molar entropy, molar heat capacity |
L 2 MT -2 q -1 N -1 |
joule per mole kelvin |
J / (mol × K) |
m 2 × kg × s -2 × K -1 × mol -1 |
|
|
watt per steradian |
m 2 × kg × s -3 × sr -1 |
||||
| Exposure dose (X-ray and gamma radiation) |
pendant per kilogram |
||||
| Absorbed dose rate |
gray per second |
||||
3. UNITS NOT INCLUDED IN THE SI
3.1. The units listed in table. 6, are allowed for use without any time limit on a par with SI units. 3.2. Without limiting the term, it is allowed to use relative and logarithmic units, with the exception of the unit neper (see p. 3.3). 3.3. The units shown in table. 7 is temporarily allowed to be applied pending the adoption of relevant international decisions on them. 3.4. Units, the ratios of which with SI units are given in reference annex 2, are withdrawn from circulation within the time frames provided for by the programs of measures for the transition to SI units, developed in accordance with RD 50-160-79. 3.5. In justified cases, in sectors of the national economy, it is allowed to use units that are not provided for by this standard, by introducing them into industry standards in agreement with the State Standard.Table 6
Non-SI units allowed for use on a par with SI units
|
Name of quantity |
Note |
||||
|
Name |
Designation |
Correlation with the SI unit |
|||
|
international |
|||||
| Weight | |||||
|
atomic mass unit |
1.66057 × 10 -27 × kg (appr.) |
||||
| Time 1 | |||||
|
86400 s |
|||||
| Flat angle |
(p / 180) rad = 1.745329 ... × 10 -2 × rad |
||||
|
(p / 10800) rad = 2.908882 ... × 10 -4 rad |
|||||
|
(p / 648000) rad = 4.848137 ... 10 -6 rad |
|||||
| Volume, capacity | |||||
| Length |
astronomical unit |
1.49598 × 10 11 m (appr.) |
|||
|
light year |
9.4605 × 10 15 m (appr.) |
||||
|
3.0857 × 10 16 m (appr.) |
|||||
| Optical power |
diopter |
||||
| Square | |||||
| Energy |
electron-volt |
1.60219 x 10 -19 J (appr.) |
|||
| Full power |
volt-ampere |
||||
| Reactive power | |||||
| Mechanical stress |
newton per square millimeter |
||||
| 1 It is also allowed to use other units that have become widespread, for example, week, month, year, century, millennium, etc. 2 It is allowed to use the name "gon" 3 It is not recommended to use it for precise measurements. If it is possible to shift the designation l with the number 1, the designation L is allowed. Note. Units of time (minute, hour, day), flat angle (degree, minute, second), astronomical unit, light year, diopter and atomic mass unit are not allowed to be used with prefixes | |||||
Table 7
Units temporarily admitted for use
|
Name of quantity |
Note |
||||
|
Name |
Designation |
Correlation with the SI unit |
|||
|
international |
|||||
| Length |
nautical mile |
1852 m (exact) |
In nautical navigation |
||
| Acceleration |
In gravimetry |
||||
| Weight |
2 × 10 -4 kg (exact) |
For gems and pearls |
|||
| Linear density |
10 -6 kg / m (exact) |
In the textile industry |
|||
| Speed |
In nautical navigation |
||||
| Rotation frequency |
revolution per second |
||||
|
rpm |
1/60 s -1 = 0.016 (6) s -1 |
||||
| Pressure | |||||
| Natural logarithm of the dimensionless ratio of a physical quantity to a physical quantity of the same name, taken as the initial one |
1 Np = 0.8686 ... V = 8.686 ... dB |
||||
4. RULES FOR THE FORMATION OF DECIMAL MULTIPLE AND PRICE UNITS, AS WELL AS THEIR NAMES AND DESIGNATIONS
4.1. Decimal multiples and sub-multiples, as well as their names and designations, should be formed using the factors and prefixes given in table. eight.Table 8
Multipliers and prefixes for the formation of decimal multiples and sub-multiples and their names
|
Factor |
Prefix |
Prefix designation |
Factor |
Prefix |
Prefix designation |
||
|
international |
international |
||||||
5. RULES FOR WRITING THE DESIGNATIONS OF UNITS
5.1. To write the values of quantities, the designation of units by letters or special characters (... °, ... ¢, ... ¢ ¢) should be used, and two types of letter designations are established: international (using letters of the Latin or Greek alphabet) and Russian (using letters of the Russian alphabet) ... The unit designations established by the standard are given in table. 1 - 7. International and Russian designations for relative and logarithmic units are as follows: percentage (%), ppm (o / oo), ppm (pp m, ppm), bel (V, B), decibel (dB, dB), octave (- , oct), decade (-, dec), background (phon, background). 5.2. Letter designations of units should be printed in roman type. In the notation of units, the dot is not used as a sign of abbreviation. 5.3. Unit designations should be used after numeric: values of quantities and placed in a line with them (without wrapping to the next line). A space should be left between the last digit of the number and the designation of the unit, equal to the minimum distance between words, which is determined for each type and size of font in accordance with GOST 2.304-81. Exceptions are designations in the form of a sign raised above the line (clause 5.1), before which no space is left. (Modified edition, Amendment No. 3). 5.4. If there is a decimal fraction in the numerical value of a quantity, the unit designation should be placed after all digits. 5.5. When specifying the values of quantities with maximum deviations, the numerical values with maximum deviations should be enclosed in brackets and the designation of the unit should be impeded after the brackets or the designations of the units should be put down after the numerical value of the quantity and after its maximum deviation. 5.6. It is allowed to use the designations of units in the headings of the columns and in the names of the rows (sidebars) of the tables. Examples:|
Nominal flow rate. m 3 / h |
Upper limit of indications, m 3 |
Division price of the extreme right roller, m 3, no more |
||
|
100, 160, 250, 400, 600 and 1000 |
||||
|
2500, 4000, 6000 and 10000 |
||||
| Traction power, kW | ||||
| Overall dimensions, mm: | ||||
| length | ||||
| width | ||||
| height | ||||
| Track, mm | ||||
| Clearance, mm | ||||
APPLICATION 1
Mandatory
RULES FOR FORMATION OF COHERENT SI UNITS
Coherent derived units (hereinafter referred to as derived units) of the International System, as a rule, are formed using the simplest equations of communication between quantities (defining equations), in which the numerical coefficients are equal to 1. For the formation of derived units, the quantities in the coupling equations are taken to be equal to SI units. Example. The unit of speed is formed using the equation that determines the speed of a straight-line and uniformly moving pointv = s / t,
Where v- speed; s- the length of the covered path; t- point movement time. Substitution instead of s and t their SI units gives
[v] = [s]/[t] = 1 m / s.
Therefore, the SI unit of speed is the meter per second. It is equal to the speed of a rectilinear and uniformly moving point, at which this point in time 1 s moves at a distance of 1 m. If the relationship equation contains a numerical coefficient other than 1, then to form a coherent derivative of the SI unit, values with values in SI units are substituted into the right side, giving, after multiplying by the coefficient, a total numerical value equal to 1. Example. If the equation is used to form a unit of energy
Where E- kinetic energy; m is the mass of a material point; v is the speed of movement of a point, then a coherent unit of SI energy is formed, for example, as follows:
Therefore, the unit of SI energy is the joule (equal to the Newton meter). In the examples given, it is equal to the kinetic energy of a body with a mass of 2 kg, moving at a speed of 1 m / s, or a body with a mass of 1 kg, moving at a speed
APPLICATION 2
Reference
The ratio of some non-SI units to SI units
|
Name of quantity |
Note |
||||
|
Name |
Designation |
Correlation with the SI unit |
|||
|
international |
|||||
| Length |
angstrom |
||||
|
x-unit |
1.00206 × 10 -13 m (appr.) |
||||
| Square | |||||
| Weight | |||||
| Solid angle |
square degree |
3.0462 ... × 10 -4 sr |
|||
| Strength, weight | |||||
|
kilogram-force |
9.80665 N (exact) |
||||
|
kilopond |
|||||
|
gram-force |
9.83665 × 10 -3 N (exact) |
||||
|
ton-force |
9806.65 N (exact) |
||||
| Pressure |
kilogram-force per square centimeter |
98066.5 Ra (exactly) |
|||
|
kilopond per square centimeter |
|||||
|
millimeter of water column |
mm water Art. |
9.80665 Ra (exact) |
|||
|
millimeter of mercury |
mmHg Art. |
||||
| Voltage (mechanical) |
kilogram-force per square millimeter |
9.80665 × 10 6 Ra (exact) |
|||
|
kilopond per square millimeter |
9.80665 × 10 6 Ra (exact) |
||||
| Work, energy | |||||
| Power |
Horsepower |
||||
| Dynamic viscosity | |||||
| Kinematic viscosity | |||||
|
ohm-square millimeter per meter |
Ohm × mm 2 / m |
||||
| Magnetic flux |
maxwell |
||||
| Magnetic induction | |||||
|
gplbert |
(10/4 p) A = 0.795775 ... A |
||||
| Magnetic field strength |
(10 3 / p) A / m = 79.5775 ... A / m |
||||
| Heat amount, thermodynamic potential (internal energy, enthalpy, isochoric-isothermal potential), heat of phase transformation, heat of chemical reaction |
calorie (int.) |
4.1858 J (exact) |
|||
|
thermochemical calorie |
4.1840 J (appr.) |
||||
|
calorie 15-degree |
4.1855 J (appr.) |
||||
| Absorbed radiation dose | |||||
| Equivalent dose of radiation, equivalent dose indicator | |||||
| Exposure dose of photon radiation (exposure dose of gamma and X-ray radiation) |
2.58 × 10 -4 C / kg (exact) |
||||
| Nuclide activity in a radioactive source |
3,700 × 10 10 Bq (exact) |
||||
| Length | |||||
| Angle of rotation |
2 p rad = 6.28 ... rad |
||||
| Magnetomotive force, magnetic potential difference |
amperage |
||||
| Brightness | |||||
| Square | |||||
APPLICATION 3
Reference
1. The choice of a decimal multiple or sub-multiple of a SI unit is dictated primarily by the convenience of its use. From the variety of multiples and sub-multiples that can be formed using prefixes, a unit is chosen that leads to numerical values of a quantity that are acceptable in practice. In principle, multiples and sub-multiples are chosen so that the numerical values of the quantity are in the range from 0.1 to 1000. 1.1. In some cases, it is advisable to use the same multiple or sub-multiple unit, even if the numerical values are outside the range from 0.1 to 1000, for example, in tables of numerical values for one value or when comparing these values in the same text. 1.2. In some areas, the same multiples or sub-multiples are always used. For example, in drawings used in mechanical engineering, linear dimensions are always expressed in millimeters. 2. Table 1 of this annex shows the recommended multiples and sub-multiples of SI units for use. Presented in table. 1 multiples and sub-multiples of SI units for a given physical quantity should not be considered exhaustive, since they may not cover the ranges of physical quantities in the developing and newly emerging fields of science and technology. Nevertheless, the recommended multiples and sub-multiples of SI units contribute to the uniformity of the representation of the values of physical quantities related to various fields of technology. The same table also contains multiples and sub-multiples of units used on a par with SI units, which have become widespread in practice. 3. For values not covered by the table. 1, multiples and sub-multiples should be used, selected in accordance with paragraph 1 of this appendix. 4. To reduce the likelihood of errors in calculations, decimal multiples and sub-multiples are recommended to be substituted only in the final result, and in the process of calculations all values are expressed in SI units, replacing prefixes with powers of 10. 5. In table. 2 of this annex shows the common units of some logarithmic quantities.Table 1
|
Name of quantity |
Designations |
|||
|
SI units |
units not included in the SI |
multiples and sub-multiples of non-SI units |
||
|
Part I. Space and time |
||||
| Flat angle |
rad; glad (radian) |
m rad; mkrad |
... ° (degree) ... (minute) ... "(second) |
|
| Solid angle |
sr; cp (steradian) |
|||
| Length |
m; m (meter) |
… ° (degree) … ¢ (minute) … ² (second) |
||
| Square | ||||
| Volume, capacity |
l (L); l (liter) |
|||
| Time |
s; s (second) |
d; day (day) min; min (minute) |
||
| Speed | ||||
| Acceleration |
m / s 2; m / s 2 |
|||
|
Part II. Periodic and related phenomena |
||||
|
Hz; Hz (hertz) |
||||
| Rotation frequency |
min -1; min -1 |
|||
|
Part III. Mechanics |
||||
| Weight |
kg; kg (kilogram) |
t; t (ton) |
||
| Linear density |
kg / m; kg / m |
mg / m; mg / m or g / km; g / km |
||
| Density |
kg / m 3; kg / m 3 |
Mg / m 3; Mg / m 3 kg / dm 3; kg / dm 3 g / cm 3; g / cm 3 |
t / m 3; t / m 3 or kg / l; kg / l |
g / ml; g / ml |
| Movement amount |
kg × m / s; kg × m / s |
|||
| Momentum moment |
kg × m 2 / s; kg × m 2 / s |
|||
| Moment of inertia (dynamic moment of inertia) |
kg × m 2, kg × m 2 |
|||
| Strength, weight |
N; N (newton) |
|||
| Moment of power |
N × m; N × m |
MN × m; MN × m kN × m; kN × m mN × m; mN × m m N × m; μN × m |
||
| Pressure |
Ra; Pa (pascal) |
m Pa; μPa |
||
| Voltage | ||||
| Dynamic viscosity |
Pa × s; Pa × s |
mPa × s; mPa s |
||
| Kinematic viscosity |
m 2 / s; m 2 / s |
mm 2 / s; mm 2 / s |
||
| Surface tension |
mN / m; mN / m |
|||
| Energy, work |
J; J (joule) |
(electron-volt) |
GeV; GeV MeV; MeV keV; keV |
|
| Power |
W; W (watt) |
|||
|
Part IV. Heat |
||||
| Temperature |
TO; K (kelvin) |
|||
| Temperature coefficient | ||||
| Heat, amount of heat | ||||
| Heat flow | ||||
| Thermal conductivity | ||||
| Heat transfer coefficient |
W / (m 2 × K) |
|||
| Heat capacity |
kJ / K; kJ / K |
|||
| Specific heat |
J / (kg × K) |
kJ / (kg × K); kJ / (kg × K) |
||
| Entropy |
kJ / K; kJ / K |
|||
| Specific entropy |
J / (kg × K) |
kJ / (kg × K); kJ / (kg × K) |
||
| Specific amount of heat |
J / kg; J / kg |
MJ / kg; MJ / kg kJ / kg; kJ / kg |
||
| Specific heat of phase transformation |
J / kg; J / kg |
MJ / kg; MJ / kg kJ / kg; kJ / kg |
||
|
Part V. Electricity and magnetism |
||||
| Electric current (strength of electric current) |
A; A (ampere) |
|||
| Electric charge (amount of electricity) |
WITH; Cl (pendant) |
|||
| Spatial density of electric charge |
C / m 3; Cl / m 3 |
C / mm 3; Cl / mm 3 MS / m 3; MCL / m 3 C / s m 3; Cl / cm 3 kC / m 3; kC / m 3 m C / m 3; mC / m 3 m C / m 3; μC / m 3 |
||
| Surface electric charge density |
С / m 2, Kl / m 2 |
MS / m 2; MCL / m 2 C / mm 2; Cl / mm 2 C / s m 2; Cl / cm 2 kC / m 2; kC / m 2 m C / m 2; mC / m 2 m C / m 2; μC / m 2 |
||
| Electric field strength |
MV / m; MV / m kV / m; kV / m V / mm; V / mm V / cm; In / cm mV / m; mV / m m V / m; μV / m |
|||
| Electric voltage, electric potential, electric potential difference, electromotive force |
V, V (volts) |
|||
| Electrical displacement |
C / m 2; Cl / m 2 |
C / s m 2; Cl / cm 2 kC / cm 2; kC / cm 2 m C / m 2; mC / m 2 m С / m 2, μC / m 2 |
||
| Electric displacement flux | ||||
| Electrical capacity |
F, F (farad) |
|||
| Absolute dielectric constant, electric constant |
m F / m, μF / m nF / m, nF / m pF / m, pF / m |
|||
| Polarization |
С / m 2, Kl / m 2 |
S / s m 2, C / cm 2 kC / m 2; kC / m 2 m С / m 2, mC / m 2 m C / m 2; μC / m 2 |
||
| Electric moment of the dipole |
С × m, Kl × m |
|||
| Electric current density |
A / m 2, A / m 2 |
MA / m 2, MA / m 2 A / mm 2, A / mm 2 A / s m 2, A / cm 2 kA / m 2, kA / m 2, |
||
| Linear density of electric current |
kA / m; kA / m A / mm; A / mm A / s m; A / cm |
|||
| Magnetic field strength |
kA / m; kA / m A / mm; A / mm A / cm; A / cm |
|||
| Magnetomotive force, magnetic potential difference | ||||
| Magnetic induction, magnetic flux density |
T; Tl (tesla) |
|||
| Magnetic flux |
Wb, Wb (weber) |
|||
| Magnetic vector potential |
T × m; T × m |
kT × m; kT × m |
||
| Inductance, mutual inductance |
H; Mr (henry) |
|||
| Absolute magnetic permeability, magnetic constant |
m H / m; μH / m nH / m; nH / m |
|||
| Magnetic moment |
A × m 2; A m 2 |
|||
| Magnetization |
kA / m; kA / m A / mm; A / mm |
|||
| Magnetic polarization | ||||
| Electrical resistance | ||||
| Electrical conductivity |
S; See (siemens) |
|||
| Specific electrical resistance |
W × m; Ohm × m |
G W × m; GOm × m M W × m; MOhm × m k W × m; kΩ × m W × cm; Ohm × cm m W × m; mΩ × m m W × m; μΩ × m n W × m; nOhm × m |
||
| Specific electrical conductivity |
MS / m; MSm / m kS / m; kS / m |
|||
| Reluctance | ||||
| Magnetic conductivity | ||||
| Impedance | ||||
| Impedance modulus | ||||
| Reactance | ||||
| Active resistance | ||||
| Admittance | ||||
| Admittance module | ||||
| Reactive conductivity | ||||
| Conductance | ||||
| Active power | ||||
| Reactive power | ||||
| Full power |
V × A, B × A |
|||
|
Part VI. Light and associated electromagnetic radiation |
||||
| Wavelength | ||||
| Wave number | ||||
| Radiation energy | ||||
| Radiation flux, radiation power | ||||
| Luminous energy (radiant intensity) |
W / sr; W / Wed |
|||
| Energy brightness (radiance) |
W / (sr × m 2); W / (sr × m 2) |
|||
| Energy illumination (irradiance) |
W / m 2; W / m 2 |
|||
| Energetic luminosity (irradiance) |
W / m 2; W / m 2 |
|||
| The power of light | ||||
| Light flow |
lm; lm (lumen) |
|||
| Light energy |
lm × s; lm × s |
lm × h; lm × h |
||
| Brightness |
cd / m 2; cd / m2 |
|||
| Luminosity |
lm / m 2; lm / m 2 |
|||
| Illumination |
l x; lux (lux) |
|||
| Light exposure |
lx × s; lx × s |
|||
| Luminous equivalent of radiation flux |
lm / W; lm / W |
|||
|
Part VII. Acoustics |
||||
| Period | ||||
| Batch frequency | ||||
| Wavelength | ||||
| Sound pressure |
m Pa; μPa |
|||
| Particle Oscillation Speed |
mm / s; mm / s |
|||
| Volumetric velocity |
m 3 / s; m 3 / s |
|||
| Sound speed | ||||
| Sound energy flow, sound power | ||||
| Sound intensity |
W / m 2; W / m 2 |
mW / m 2; mW / m 2 m W / m 2; μW / m 2 pW / m 2; pW / m2 |
||
| Specific acoustic resistance |
Pa × s / m; Pa × s / m |
|||
| Acoustic impedance |
Pa × s / m 3; Pa × s / m 3 |
|||
| Mechanical resistance |
N × s / m; N × s / m |
|||
| Equivalent absorption area of a surface or object | ||||
| Reverberation time | ||||
|
Part VIII Physical chemistry and molecular physics |
||||
| Amount of substance |
mol; mol (mol) |
kmol; kmol mmol; mmol m mol; μmol |
||
| Molar mass |
kg / mol; kg / mol |
g / mol; g / mol |
||
| Molar volume |
m 3 / moi; m 3 / mol |
dm 3 / mol; dm 3 / mol cm 3 / mol; cm 3 / mol |
l / mol; l / mol |
|
| Molar intrinsic energy |
J / mol; J / mol |
kJ / mol; kJ / mol |
||
| Molar enthalpy |
J / mol; J / mol |
kJ / mol; kJ / mol |
||
| Chemical potential |
J / mol; J / mol |
kJ / mol; kJ / mol |
||
| Chemical affinity |
J / mol; J / mol |
kJ / mol; kJ / mol |
||
| Molar heat capacity |
J / (mol × K); J / (mol × K) |
|||
| Molar entropy |
J / (mol × K); J / (mol × K) |
|||
| Molar concentration |
mol / m 3; mol / m 3 |
kmol / m 3; kmol / m 3 mol / dm 3; mol / dm 3 |
mol / 1; mol / L |
|
| Specific adsorption |
mol / kg; mol / kg |
mmol / kg; mmol / kg |
||
| Thermal diffusivity |
M 2 / s; m 2 / s |
|||
|
Part IX. Ionizing radiation |
||||
| Absorbed dose of radiation, kerma, absorbed dose index (absorbed dose of ionizing radiation) |
Gy; Gr (gray) |
m G y; μGy |
||
| Nuclide activity in a radioactive source (radionuclide activity) |
Bq; Bq (becquerel) |
|||
table 2
|
Name of the logarithmic quantity |
Unit designation |
Initial value of the quantity |
| Sound pressure level | ||
| Sound power level | ||
| Sound intensity level | ||
| Difference in power levels | ||
| Strengthening, weakening | ||
| Attenuation coefficient |
APPLICATION 4
Reference
