Catálogo General de Material para Laboratorio

12 KNOWLEDGE Quantities and units Quantity Legal units Units no longer approved Conversion factors/ Relationships Comments Name Symbol Name Symbol activity of a radioactive substance becquerel Bq Curie Ci 1 Bq 1 Ci = 1 s -1 = 3,7 · 10 10 s -1 SI unit equivalent dosage sievert Sv Rem rem 1 Sv 1 rem = 1 J/kg = 10 -2 J/kg SI unit work, mechanical joule J Erg erg 1 J 1 erg = 1 N · m= 1 kg · m 2 /s 2 = 10 -7 J SI unit luminous intensity lux lx Nox nx 1 lx 1 nx = 1 lm/m 2 = 10 -3 lx SI unit lens power of optical systems diopter dpt 1 dpt = 1 m -1 (also called refractive power density kilogram divided by cubic meter kg/m 3 SI unit usually expressed in g/ml or g/cm 3 rotation, specific rad · m 2 /kg degree · dm –1 · g –1 · ml degree [ a ] d l c = a / (l · c) = amount of rotation in degrees = polarimeter tube length in dm = concentration in g/ml SI unit usually expressed in degrees amount of rota- tion caused by 1 g sub- stance in 1 ml solution in a tube 10 cm long) rotational speed rotations divi- ded by seconds rotations divi- ded by minutes s –1 min –1 RPM 1 RPM = 1 min –1 = 1/60 s –1 = 1/60 Hz SI unit pressure Pascal Bar Pa bar phys. atmosph. techn. atmosph. techn. atmosph. above atm meter water gage millimeter mercury or torr atm at atü mWG mm Hg torr 1 Pa 1 bar 1 atm 1 at atü 1 mWG 1 mm Hg = 1 N/m 2 = 10 5 Pa = 1,01325 · 10 5 Pa = 1 kp/cm 2 = 0,9807 · 10 5 Pa = atm + 1 = 9,790 · 10 3 Pa = 1 Torr = 1,3332 · 10 2 Pa SI unit also refer to tables “Conversion factors for units of pressure“ and “Conversion of English to metric units energy joule electron volt J eV calory cal 1 J 1 eV 1 cal = 1 N · m = 1 kg · m 2 /s = 1 W · s = 1,60219 · 10 -19 J = 4,1868 J SI units absorbed dose Gray Gy Rad Rem rd rem 1 Gy 1 rd 1 rem = 1 J/kg = 0,01 J/kg = 0,01 J/kg SI unit absorbed dosage rate/power Gray divided by second Gy/s 1 Gy/s = 1 W/kg SI unit extinction coefficient, molarer specific l/mol · cm l/g · cm also called spectral ab- sorption factor (DIN) or in- ternal absorbency (IUPAC)