Converting Metric Units And Si Units - YASKAWA VS-626M5 Instruction Manual

Appendix

15.2.4 Converting Metric Units and SI Units

15.2.4 Converting Metric Units and SI Units
15
This manual uses SI units. SI units differ from the metric units for gravity used to date, so conversion is
necessary. Table 15.2 shows how to convert the main units of gravity and force to SI units.
Table 15.2 Metric Units and SI Units Conversion Table
Quantity Metric Unit
Force and Load kgf
Weight
kgf
2
Mass
kgf s /m
S
Torque kgf m
S
2
Inertial Moment
gf cm s
S S
Speed (Revolu-
rpm
tions)
Vibration G
Note: The relationship between the metric GD
2
GD = 4J.
SI Unit
N 1 kgf = 9.80665 N
The metric unit for weight and the SI unit
---
for mass are the same. (Mass expressed us-
ing SI units for bodies in the metric mea-
surement for weight Wkgf are expressed as
kg
Wkg.
N m 1 kgf
S
2
kg m 1 gf
S
−1
min 1 rpm = 1 min
2
m/s 1 G = 9.80665 m/s
2
and the SI unit for inertial moment is as follows:
15 -10
Conversion
g
t f i ht Wk f
m = 9.80665 N m
S S
2 −5 2
cm s = 9.80665 x 10 kg m
S S S
−1
2
d