User manual

F-2 8580/8590 Vehicle-Mount Computer User Manual
Appendix F: Mechanical Dynamic Loading
Units without Vibration Isolation (tuned to high frequency)
(5)M1 Stationary Use
Operational environments with low energy vibrations and medium energy shocks as well as
very careful handling/transport compliant with:
• Operation class 5M1 according to DIN EN 60721-3-5.
• Examples: Vehicles with very good shock absorption: Car dashboard, immobile mount-
ing surfaces: Desk or wall.
F.2 Units without Vibration Isolation (tuned to high frequency)
Selection criteria: Stationary, partly mobile or fully mobile applications for which compo-
nents offering isolation against vibrations cannot be used or are not required.
Because of variable mountings options, 8580/8590 units form a spring-mass system that can
result in excitation by one or more random vibrations or shocks from the surroundings.
This system reacts with natural oscillations, the amplitudes of which can be up to 20 times
greater than the excitation amplitudes (resonance effects). The goal is therefore to remove
resonance points of this kind or at least to tune the system to such a high frequency that they
fall within the range of low excitation amplitudes.
For an initial assessment, you can test the device by hand. Bring the system to excitation by
gently hitting it with your hand. If the 8580/8590 starts to visibly oscillate and if the vibra-
tions take a long time to die away, it is probable that the natural frequency is too low. In this
case, we recommend reinforcing the fixing points to the maximum bending moments
(through the use of rigid sections, for example).
Practically speaking, natural frequencies above 100 Hz are sufficient. However, those below
50 Hz are likely to lead to damaging amplitudes during resonance which may result in
fatigue fractures along the outer mounting parts or on the internal electronic components or
even a loosening of the connections.
F.3 Passive Vibration Isolation (tuned to low frequency)
Selection criteria: Mobile use
For example, you can attach the mounting bracket to elastomer springs or rubber buffers.
Important: The 8580/8590 system can vibrate and should therefore be installed
using the bracket as rigidly as possible.
Note: The system can be tuned to a low frequency by installing a flexible bearing.