What to Look for in a Replacement Vibration Test Controller

Vibration Control

With proper maintenance, a vibration controller should be serviceable for many years. However, if your current controller is out for calibration or simply not working as needed, a replacement vibration test controller may be necessary. There are several reasons for replacing a vibration controller, including:

    • Compatibility with a new version of Windows OS
    • Improved testing/graphing/reporting capability
    • More computation and advanced control techniques
    • Support for more applications
    • The capability of meeting new test standards/requirements

Vibration Research offers both industry-leading software and a hassle-free method for replacing your vibration test controller.

How Often Are Vibration Testing System Components Replaced?

There are five main components of a vibration testing system:

    • Vibration Controller
    • Vibration Control Software
    • Power Amplifier
    • Shaker
    • Accelerometers and other sensors

Shakers

A properly maintained shaker can be in service for decades. They can be used for as long as the replacement parts are available. Common components that will require replacement include:

    • Armature rewind: after the armature coil fatigues to a point of failure, it may need to be re-wound.
    • Armature replacement: in the case of physical damage, the armature will need to be replaced.
    • Flexures or support bearings: the most replaced component; the flexures or support bearings tied between the fixed body of the shaker and the moving armature and are subject to mechanical fatigue. They will require replacement after continued bending.
    • Sensors used to monitor/limit total travel or temperature: Sensors will fail over time and may need to be replaced.

All-in-all, shakers are robust and can be used for 20+ years when properly maintained. Newer shakers have more capability than many old shakers, especially in terms of the amount of displacement/velocity that can be generated. Three-inch stroke shakers are common in newer models and create many testing opportunities but are not necessary for all situations.

Power Amplifier

The power amplifier has a typical lifetime of 15-20 years. Power modules can be damaged during testing but can be replaced. Eventually, the power modules and other replacement parts become unavailable or expensive due to a lack of availability. However, most amplifier companies can retrofit a power amplifier with any shaker model.

Vibration Controller

VR9500

The vibration controller is the primary tool for generating the output signal sent to the amplifier and measuring the control and response sensors on the shaker. Along with the control software, the controller is the most critical component of the shaker system.

Most vibration controllers should be replaced every ten years. The control software should be routinely updated to make sure the software can meet the requirements of the latest test standards and function with the latest versions of Windows.

Compared to other components, the vibration controller has the most complex electronics. The electronics industry continuously releases new designs/capabilities for ADC, DAC, processors, FPGAs, and other components used to control and analyze a vibration test. This constant advancement generally results in older parts becoming obsolete. A vibration controller 20+ years in age will, most likely, be unrepairable in the event of damage because of the lack of availability of the replacement parts.

What to Look for in a Replacement Vibration Test Controller

When searching for a replacement vibration test controller, both the hardware and software should be considered. Vibration control software allows for the dynamic control of data and vibration controllers monitor and regulates signals with precision. Both must operate efficiently to run a successful vibration test.

To view the many capabilities of vibration control software, jump over to our VibrationVIEW and ObserVIEW software packages. Below, we list several features to consider when selecting new vibration control hardware.

Input channels and scalability

Channel count requirements depend on the number of locations data will be collected from. For a large device, such as a satellite, engineers use hundreds of channels to collect data. A high channel count is also necessary for processing a high amount of data.

The VR9500 is scalable from 1 to 128 channels and the VR10500 is scalable from 16 to 256 channels. Each four-channel module (VR9500) or 16-channel module (VR10500) can be used independently on separate shakers or linked into a single stack for jobs requiring a higher channel count. The ObserVR1000 dynamic system analyzer can be used as a controller in 16 channel units and up to 128 channels.

Sample rate

In vibration testing, the sample rate controls the rate of analog-to-digital signal conversion. A high sample rate acquires more data in a timeframe and can be used to form a more accurate representation of the original signal. As the sample rate increases, the reconstruction of the signal gets closer to “perfect.” Note that perfect reconstruction is possible only in theory.

The control rate is based on the Nyquist rate, which is about half of the sample rate. Sampling over the Nyquist rate will result in over-sampling and sampling under the Nyquist rate will result in under-sampling.

The VR9500 has up to a 200kHz sample rate with up to 50kHz control, the VR10500 has up to a 256kHz sample rate, and the ObserVR100 has up to a 128kHz sample rate.

Lines of resolution

Put simply, the lines of resolution determine the resolution of a vibration spectrum. A lines of resolution value will include more spectral lines. A higher lines of resolution value is beneficial for low-frequency control and a more accurate excitation of resonances.

All Vibration Research controllers have 26,000 lines of resolution.

Dynamic range

The dynamic range represents the range of voltage that can be properly controlled during a test. The maximum signal level, noise floor, and harmonic distortion determine the limits of a controller and make up its dynamic range. Test equipment, such as a vibration controller, can never have too high of a dynamic range.

Support

More generally and possibly most importantly, the reputation of the manufacturer should be reviewed. Once a vibration control system is purchased, a responsive support team is a necessary tool for success moving forward.

At Vibration Research, we develop our own hardware and our products are known for their reliability. VR warrants the controller hardware to be free of defects in materials and workmanship for the lifetime of the product.

Additionally, ongoing support is just as important to us as the initial installation. Our support team is available to help with test profile creation, assist with test troubleshooting, help with custom forms and reports, and give instruction regarding theory and application support.

VR Controllers: Compatible with All Shakers and PCs

First and most importantly, Vibration Research controllers are compatible with all electrodynamic, servo-hydraulic, and servo-electric shakers. VR controllers can be added to any test setup, which can significantly reduce the cost of new equipment. The VibrationVIEW software, which can be run on all our hardware options, includes single-axis, dual-axis, dual-phase, rotational, three-axis, multi-loop/four-post, and seismic control options.

Additionally, any personal computer (PC) can be used to run VR software because the license key is carried in the controller. For some vibration control systems, the software is licensed to one PC and the same PC must be used every time.

When you switch to a VR controller, you can use your current testing equipment. Of course, if you’d like to replace your shaker, we’d be happy to help you there, too. You can view our current shaker systems here.

With the VR guarantee, try our hardware and software fully enabled for 30 days. We are confident you’ll choose VR for replacement vibration test controllers moving forward.

VR Vibration Controller Features

VR vibration controllers are dependable and intuitive. Paired with our industry-leading control software and reliable support team, Vibration Research is the smart choice when replacing a vibration test controller. Our hardware systems come with a lifetime guarantee and free demo units with all software enabled.

    • VR9500: lower channel count with mix-and-match capabilities
    • VR10500: 16 channel minimum enclosure with highest specifications
    • ObserVR1000: all-in-one Dynamic Signal Analyzer that also can serve as a vibration controller

Interested in learning more? Visit the products page or view our support services.

Date

August 24, 2020

Author

Cherie Stoll

Category

Vibration Control

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