Reuben Hale, P.E.
Ph: (510) 507-1300
Vibration Characterization involves documenting the offending disturbances in the time domain and/or frequency domain. Steady vibration disturbances are often best characterized by the frequency components of the disturbance. Transient disturbances are often characterized in the Time Domain. We analyze the disturbance in both domains using a variety of signal processing and analysis hardware and software, however our most valuable resource is our experience and judgment.
| Semiconductor AFM Tool Response to |
|Fatigue Cracking on Turbine foundation|
Note that we very often make measurements of different signal types, such as vibration, acoustic noise, pressure, strain, air flow, current, voltage, etc. Making a measurement that is actually useful can be challenging and depends not only on the quality of the measurement, but also on an understanding of the particular structural dynamics at hand.
For instance, our initial evaluation of the dynamics influences the choice of measurement location, sensor, sensor mounting, length of capture, bandwidth, windowing, and an idea of what to expect and how to interpret it. We provide this understanding as part of our vibration testing services to quickly and efficiently characterize the root of the vibration problem and the dynamics at play.
| Shipping Vibration Characterization|
for Hard Disk Rack
|Hard Disk Rack Vibration Test Rolling Over Bumps|
In the real world there are judgments that must be made as to where to mount sensors to capture a good representation of the vibration response. Often we are testing structures and products that are not complete, partially built and missing components. This is because the working products are often in use. We look at the working equipment, structures, products, consider the mass distribution, stiffness peculiarities, how pieces are put together on the working system, and come up with modifications to the test setup to better represent real structure.
|Semiconductor Turbo Pump Characterization|| Helecopter Instrument Vibraiton, Engine Mount |
This is our Bread and Butter and we are good at it.
Here is a list of some common vibration characterization measurements:
- Acceleration - Using single and tri-axial accelerometers of various form factors and sensitivities
- Displacement - Using the filtered integral of acceleration
- Relative displacement - Measured directly between critical components using a variety non-contact sensors, with sub-nanometer resolution
- Velocity - Used for comparison with various industry standards, or velocity ripple on a scanning stage system, or 1/3 octave band floor rms floor velocity levels.
- Rotation can be measured in a number of ways but it is often best to measure it directly.
- Rotational velocity can also be measured in a number of ways but is also often best to used a sensor specifically designed to measure rotational velocity.
- Strain - Used to identify force transmission path, structural integrity, as a sensor for dynamic measurement.
- Magnetic Field
- Light Intensity
- Any signal
We consider the expected frequency range and select our sensors and their mouting dynamics appropriately. Often we dont know what to expect exactly until we are on site looking at the disturbance spectra and waveform. We then have the judgment and experience to make modifications to our test setup and instrumentation to get meaningful measurements that will answer the pertinent questions being asked.
|Thermal Performance and Vibration Optimization||Spectra of Vibration on Turbine foundation|
- Vibration Consulting Topics Include:
Overview, Vibration Characterization, Dynamic Testing, Damping Treatments, Time Domian Analysis