Comparison Passive Vs. Active
Feature
Passive
Active
Isolation Range
>5Hz
>.7Hz
Low Frequency Resonance
2 -3 Hz
None
Amplification at Resonance
4-9 times
N.A.
Load Sensitive
Yes
No
High Center of Gravity decreases efficiency
Yes
No
Stiffness
soft
500 x Stiffer than Passive
Isolation in all six degrees of freedom
No
Yes
Constant Compressed Air Req'd
Usually
No
AC Power
none
110-240 VAC
Settling time
1-5 Sec
10-20 msec
Auto Leveling
Yes
Yes