14 KNOWLEDGE Quantities and units (continued) Quantity Legal units Units no longer approved Conversion factors/ Relationships Comments Name Symbol Name Symbol illumination candelas divide by square meters cd/m2 Nit Stilb Lambert nt sb la 1 nt 1 sb 1 la = 1 cd/m2 = 1 cd/cm2 = 1 πsb = 1 πcd/cm2 SI unit luminance, specific lumens divided by square meters lm/m2 Phot ph 1 ph = 1 lm/cm2 SI unit luminous intensity candela cd Hefner candela Internat. candela HK IK 1HK 1 IK = 0,903 cd = 1,019 cd SI basic unit luminous flux lumen lm 1 lm = 1 cd · sr SI unit mass (weight as result of weighing) kilogram gram ton metric carat atomic mass unit kg g t Kt u Dalton gr. amu 1 g 1 t 1 Kt 1 u 1 Dalton = 10–3 kg = 103 kg = 0,2 g = 1,6605 · 10-27 kg = 1,6602 · 10-27 kg SI basic unit (only for precious stones) voltage, electrical volt V Internat. Volt Vint 1 V 1 Vint = 1 J/C = 1 W/A = 1,00034 V SI unit, (also electr. potential) amount of substance mol mol Mol amount Gram-molecule Gram-atom Gram- equivalent Mol Mol Tom Val SI basic unit 1 mol equsls 6,022 · 1023 particles (atoms, moleules, ions, electroncs, photons), i.e. as many elementary units as are contained in 12 g of the nucleotide carbon 12 (Avogadro’s number) proportion of substance mol/mol % Mol fraction (also called amount of substance) amount of substance concentration, in relation to equivalents mol/l mol/l Molarity Molality Normaliy mol/kg val/l current intensity, electrical ampere A Internat. Ampere Aint 1 A 1 Aint = 1 C/s = 1,000291 A SI basic unit temperature kelvin degree Celsius K °C Degree kelvin Degree fahrenheit Degree rankine Degree reaumur °K °F °Rank °R K °C °K °F °Rank °R = °C + 273,15 = °K - 273,15 = °K = 1,8 K - 459,4 = 1,8 K = 1,25 °C SI basic unit. refer also to the table “Conversion formulae for temperatures“ (symbol also °R) viscosity, dynamic kinematic Pa · s m2/s Poise Stokes P St 1 Pa · s 1 P 1 St = 1 N · s · m2 = 1 kg/s · m = 0,1 Pa · s = 1 cm2/s SI unit SI unit
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