How much do your systems cost?
- Contact us for a price quote today.
How can I address noise coming in from my cables?
- Please refer to our tutorial on cable management.
How do I determine how much isolation I need?
- The most surefire way to determine the level of noise reduction you need is to compare the allowable noise specification for your instrument to the level of noise in your environment.
- The allowable noise specification can usually be found in the installation requirements document for your instrument. If you do not have that document, contact the instrument’s manufacturer to find out the allowable noise specifications. The level of noise in your environment can be found by performing a site survey. Often, a site survey is performed by the instrument manufacturer at the time of purchase. If a site survey was not performed or the results are no longer available, a new survey should be performed. Herzan offers vibration measurement equipment and site survey tools.
- Once this information is gathered, you should compare them to find the trouble areas for your instrument. For example, suppose your instrument has an allowable vibration specification of 4 um/sec rms from 15 to 25 Hz and your site survey shows an 8 um/sec rms peak at 20 Hz. Comparing the site survey data to the allowable vibration specification, you see that 8 um/sec rms exceeds 4 um/sec rms; you’ll need over 50% reduction to bring that peak within specification.
- For more information, see our Tutorial on Choosing an Isolation System.
Do you offer on-site evaluations of your systems?
- Yes! The best test of an isolation system is to observe how the system will perform with your instrument in your environment. So Herzan is happy to facilitate on-site evaluations whenever possible. Evaluations are offered free of charge. Please contact Herzan to request an evaluation.
I’m noticing 60 Hz noise in my measurements. What is causing this?
- Dramatic spikes at 60 Hz are usually associated with electronic noise. Make sure that your instrument is well-grounded. Try turning off electronic items connected to the instrument or in the vicinity.
Vibration Isolation Systems
Can I exchange my isolation system?
- Yes. If your system is still within the satisfaction guarantee period, you can exchange your isolation system for a different system. If the system is beyond the guarantee period, we still offer discounts on exchanged items which can be applied towards a new system.
How do I know if my isolation system is working?
- Is the system floating?
- Herzan isolation systems all require some ‘play’ in the system for the isolation and damping mechanisms to be effective. The active systems – TS and AVI – are much stiffer than passive systems, so they won’t be as soft. But for all systems, you should be able to push down on one corner of the system and see it bounce somewhat. If the system is completely rigid, then you won’t be enjoying any isolation. To get the system into proper adjustment, refer to the system’s Manual or the Troubleshooting page.
- What do the diagnostics tell you?
- The TS series has a front panel which will provide you with diagnostic information. Check that the ISOL. ON light is lit continuously. Scroll through the menu to the screen with the sensor displays. These should be settled, basically appearing as straight lines, but still responsive to tapping on the system.
- The AVI system has diagnostic LED lights on the controller. These lights should be off under normal circumstances. When the system is tapped or otherwise disturbed, the lights should come on briefly and go out. If the lights are on continuously, blinking without stimulus, or remain on for long periods after stimulus, the system may not be operating properly.
For the air-based isolation systems, you should be able to tell visibly if the system is inflated properly. The mounting plate should be parallel with the support frame (DT) or table (Onyx). If it is not, re-inflate the system or adjust the air pressure. If the system returns to an off-kilter or un-inflated position, the system may not be operating properly.
- Take vibration measurements
- If you have vibration measurement equipment, you can take transmissibility measurements. Using two vibration sensors – one placed on top of the isolation system and one placed directly underneath – take measurements from the two sensors at the same time. If there is no reduction being provided by the isolation system, it may not be working properly.
- What does your instrument tell you?
- If the above tests are inconclusive, the best test is always how your instrument itself is performing. For vibration isolation, the proof really is in the pudding. If you are seeing noticeable noise levels or even increased noise levels when the isolation system is installed and activated, then it may not be operating properly. Although you should make sure that there aren’t other Sources of Noise which are causing the observed noise.
- Contact Herzan
How do I determine the appropriate load capacity for an isolation system?
- For all vibration isolation systems, you will need to make sure that the system has sufficient load capacity to support the weight of your instrument. The weight of the instrument can generally be found in the documentation which comes with the instrument. If not, contact the manufacturer to get this information.
- For passive isolation systems, performance can be somewhat dependent on the load of the system on top. Generally speaking, you’ll want to have your load at or near 80% of load capacity to achieve maximum performance.
- The performance of Herzan active vibration control systems are not dependent on the load of the system on top. As long as the weight of the system on top is within the load capacity of the isolation system, you will enjoy maximum performance.
How do I determine the appropriate size isolation system for my application?
- You will first need to check that the basic dimensions of the isolation system are large enough to accommodate your instrument. For passive vibration isolation systems, you will also need to ensure that the instrument’s center of gravity (COG) is taller than half the distance between the isolators. Having a high COG on a passive isolation system will negatively impact the performance of the system.
- Herzan active vibration control systems are not sensitive to the location of the center of gravity. As long as the system is stable, maximum performance can be expected. The instrument can even hang off the sides of the isolation system without affecting the isolation performance!
How do I decide between the TS Series and the AVI Series?
Here are the key differences between the TS and AVI:
- Isolation Performance
- The TS offers active compensation from 0.7 – 1000 Hz; the AVI offers active compensation from 1 – 200 Hz. The active compensation mainly serves to remove mechanical resonances which are inherent in the instrumentation set-up. Both systems offer passive isolation beyond the active bandwidth. The effect of this performance difference will vary depending on the sensitivity of your instrument and your environment.
- Form Factor
- The TS is a rectangular system with a height of 3″. The TS is offered in four different sizes and load capacities, which can be viewed at the TS product page. The TS is a fully-integrated system, meaning all the parts are contained in one compact system which goes underneath the instrument. The TS is almost always used on a table or lab bench, directly underneath the instrument.
- The AVI consists of two isolation modules and an external controller; the modules are shaped like beams and have a height of 4.5″. The AVI is offered in a range of sizes and load capacities, which can be viewed at the AVI product page. The AVI modules support the sensitive instrumentation. The modules can be placed directly under the instrument, used under a mounting plate which supports the instrument, integrated into the table or workstation, or placed on the floor to support the entire set-up. Location of the controller is not important.
- Load Capacity
- The TS Series offers maximum load capacities of 120 kg to 300 kg, depending on the model. Standard, two-module AVI systems can support up to 1260 kg. However, since the AVI Series is modular and expandable, the system can be expanded by adding modules to accommodate very heavy loads. There is no functional limit on the load capacity of the AVI Series.
- The TS offers automatic load adjustment and plug-and-play installation. It offers an LCD screen which shows real-time vibration levels and menus for adjusting the system.
- The AVI requires an adjustment for load upon installation. The adjustment is relatively straightforward and doesn’t require special tools or training. If the load is significantly changed during the course of use, the system may need to be re-adjusted. The AVI controller features diagnostic LED lights which show that the AVI is operating properly.
- Both systems are designed to run continuously for years without ongoing maintenance.
- The AVI is less expensive than the TS system.
- Bottom Line
- The isolation performance for both systems is excellent, so only the most sensitive applications will discern a difference between the two. Thus, the TS versus AVI choice boils down to form versus function. Many people have used the TS and are more comfortable with it. It is an easy-to-use solution that has a nice design. The AVI offers great performance in a robust, versatile, and less expensive system. But it requires a little more work to install and has a more industrial look. If you are still unclear which system is right for you, please contact Herzan and we’ll be happy to make a recommendation based on your application.
How do I decide between passive vibration isolation and active vibration control?
- Please refer to the Active vs. Passive page.
How do I read a transmissibility graph?
- Good question! Transmissibility is the standard measure of the performance of an isolation system. It shows the level of reduction which the system provides over a broad frequency spectrum.
- Transmissibility is the ratio of the displacement exiting a system divided by the displacement entering a system. Thus, a measure of 1 means that there is ‘perfect’ transmission – no reduction or amplification is occurring. Transmissibility above 1 means that there is amplification happening; transmissibility below 1 means that there is reduction taking place. For example, a transmissibility of 0.01 means that only 1% of the incoming displacement is being transmitted, in other words there is 99% reduction at that point. Transmissibility is sometimes stated in decibels, in which case the same basic principles apply.
- Transmissibility is usually expressed in a graph called a transmissibility graph. The transmissibility level is on the Y axis. Frequency, stated in hertz, is along the X axis. The performance data is plotted as a line. This line is called the system’s ‘performance curve’.
How do I switch the orientation on the door to my Silencer?
- This procedure is described on Page 3 of the Silencer User Guide.
What are my choice of cable clamps?
- Each enclosure comes with a standard cable clamp. We offer several standard designs to choose from, these can be seen on the Enclosure Features page. We also offer custom cable clamps which are built to your specific needs.
How much do your enclosures cost?
- Contact us for a price quote today!
Do your enclosures come with vibration isolation?
- Our standard enclosures do not have vibration isolation systems integrated directly into them, they are primarily soundproof hoods. However, the enclosures are designed to work well with vibration isolation systems and we offer a range of isolation systems which can be added to the enclosures. We offer discounts when an acoustic enclosure is purchased with a vibration isolation system.
Can I make my enclosure taller/wider/smaller?
- Yes. We can modify our standard designs or make a custom enclosure to suit your needs.
Do you build custom enclosures?
- Yes! We offer full service design, engineering, and production services. So we can make built-to-order enclosures to suit your specific application or OEM needs. Just Contact Us, let us know what you’re trying to accomplish, and we can help you out.
Which enclosure is right for me?
- The primary difference between the different enclosures that Herzan offers is their size. You can view dimensional drawings of each enclosure on their product pages. Take the measurements of your system and determine which dimensions suit you the best. If you prefer a specific design, we can often make modifications to that design to accommodate different dimensions.
How much do your cages cost?
- Contact us for a quote today!
What sizes do your cages come in?
- All of our Faraday cages are built-to-order. We will build the cage to your specific size requirements.
How do I conduct a transmissibility test?
- A transmissibility test is a test to gauge the performance of an isolator. It is difficult to carry out transmissibility tests in the field. Ideally, transmissibility tests are performed in a quiet lab environment using a rigid support structure for the isolator. A shaker should be used to generate adequate vibration levels in a range of frequencies. Often, ambient vibration levels are too small to generate a good baseline for comparison.
- Of course, if you are hoping to gauge the performance of an isolator in-situ, you won’t have the luxury of the controlled environment described above. There are still a few things which can be done to control other variables. You should have two sensors to carry out a transmissibility test, as you’ll need to take the measurement simultaneously to generate an accurate basis for comparison. The sensors should be identical, as different sensors have different sensitivities and noise floors.
- The sensor on the isolator should be placed directly on the isolator, not on the instrument. The isolator should be placed on the ground, as a mediating structure like a table will introduce different structural resonances. The two sensors should be placed coaxially, in other words the sensor on the isolator should be located directly above the isolator on the ground. The measurements should be taken over long periods of time with a high number of samples, in order to filter out random noises.
- Once you have both data sets, divide the noise levels experienced by the sensor on the isolator by the noise from the ground sensor and you will have a rough idea of the isolation performance of your isolator.
How do I compare noise levels for different locations?
- Comparing noise levels for different locations is an important step in determining the best place to locate a sensitive instrument or production process. To do an accurate comparison of noise levels in different locations, you must control as many variables as possible to ensure that incidental noise is not obscuring the inherent noise levels. If possible, conduct the noise tests simultaneously. This may be impossible if you have only one set of vibration measurement equipment. In which case, try to conduct measurements at the same time of day.
- Ensure that you are using identical sensors and looking at identical units and frequency spans. Place the sensor in the same orientation within each location, i.e. in the middle of the room or by the door. Place the sensor on the ground, not on furniture. Note any equipment that is running at the time.
- For more information on conducting a site survey, see our Tutorial on Conducting a Site Survey.