Chapter 6 Quantities, units and symbols - Atlas Copco ...

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Multiple units. A multiple unit is formed
by an SI unit or an additional unit by the
unit being preceded by a prefix that involves
the multiplication by the power of ten.
Fourteen such prefixes are stated in international
recommendations (standards) as
set out in the table below.
Prefix
Power Designation Symbol Example
10 12 tera T 1 terajoule 1 TJ
10 9 giga G 1 gigawatt 1 GW
10 6 mega M 1 megavolt 1 MV
10 3 kilo k 1 kilometre 1 km
10 2 hectoh h 1 hectogram 1 hg
10 1 deca da 1 decalumen 1 dalm
10 –1 deci d 1 decimetre 1 dm
10 –2 centi c 1 centimetre 1 cm
10 –3 milli m 1 milligram 1 mg
10 –6 micro µ 1 micrometre 1 µm
10 –9 nano n 1 nanohenry 1 nH
10 –12 pico p 1 picofarad 1 pF
10 –15 femto f 1 femtometre 1 fm
10 –18 atto a 1 attosecond 1 as
Pressure
Pa=N/m 2 bar kp/cm 2 Torr m vp mm vp
1 10 –5 1.02 x 10 –5 7.5 x 10 –3 1.02 x 10 –4 0.102
10 5 1 1.02 750 10.2 1.02 x 10 4
9.81 x 10 4 0.981 1 735 10 10 4
133,3 1.33 x 10 –3 1.36 x 10 –3 1 1.36 x 10 –2 13,6
9.81 x 10 3 9.81 x 10 –2 0.1 73.5 1 10 3
9.81 9.81 x 10 –5 10 –4 7.35 x 10 –2 10 –3 1
Energy
J kJ kWh kpm kcal
1 10 –3 2.78 x 10 –7 0.102 2.39 x 10 –4
1000 1 2.78 x 10 –4 102 0.239
3.6 x 10 6 3.6 x 10 3 1 3.67 x 10 5 860
9.81 9.81 x 10 –3 2.72 x 10 –6 1 2.39 x 10 –3
4.19 x 10 3 4.19 1.16 x 10 –3 427 1
Power
W kpm/s kcal/s kcal/h hk
1 0.102 0.239 x 10 –3 0.860 1.36 x 10 –3
9.81 1 2.34 x 10 –3 8.43 1.33 x 10 –2
4.19 x 10 3 427 1 3.6 x 10 3 5.69
1.163 0.119 0.278 x 10 –3 1 1.58 x 10 –3
735 75 0.176 632 1