About Passive Vibration Control
Since air-based isolation systems became widely commercially available forty years ago, they have become the standard for isolation of precision instrumentation. These systems provide a high degree of noise reduction at an exceptional value. Air-based systems are offered in a wide range of sizes, form factors, and load capacities.
TECHNOLOGY BEHIND AIR-BASED ISOLATION
While many manufacturers offer large, stand-alone tables, Herzan specializes in desktop air isolation systems. We offer low-profile, high performance systems that are easy to install and use. Herzan offers two lines of desktop isolation systems: the Onyx and DT Series.
The Onyx Series is designed and manufactured by Herzan at our headquarters in Southern California. The Onyx tables come in three standard sizes and load capacities, with an additional opportunity to completely customize an Onyx table to exactly meet the specific needs of a research application. The Onyx series has been successful supporting stylus profilometers, optical microscopes, interferometers, etc.
The DT Series is designed and manufactured by Herz Company Ltd. in Japan. Herz was founded in 1979 in Yokohama to provide vibration control solutions to the Japanese research market. In 1994, they introduced the DT Series as a low-profile, desktop air system. Herzan is the exclusive distributor for Herz products in the Americas.
PRINCIPLES OF OPERATION
Both the Onyx and DT series rely on the same basic principles of isolation. Each system has a steel powder coated top plate supporting the base of the instrument. The mounting plate, in turn, rests on the pneumatic isolators to provide a neutral top plate environment. Depending on the size of the system, there are three to five isolation mechanism assemblies supporting the mounting plate. The basic components of the isolation mechanisms are a piston, diaphragm, air chamber, damping orifice, and surge tank. The piston supports the mounting plate and rests on the diaphragm. The diaphragm is a flexible bladder which provides vertical travel and imparts horizontal vibration isolation. The diaphragm forms the top and sides of the air chamber. The air chamber acts as an air spring, which provides vertical isolation. At the bottom of the air chamber is a damping orifice. When vibrations enter the system, the piston travels up and down on the diaphragm which in turn pushes air through the orifice. Air passing through the orifice converts the kinetic energy to heat, which has the effect of attenuating the resonances of the system. The surge tank acts as a ballast, imparting stability to the system.
Both systems are offered in manual or automatic load adjustment. The manual load adjustment system utilizes a hand pump to inflate the air chambers. The user must check the system regularly to ensure that it is properly inflated. The automatic load adjustment version is provided with an air regulator and height sensors. The height sensors gauge the level of compression on each side and release air accordingly. The air regulator is connected to an external air supply. When enough air escapes the system, the air regulator will sense the decreased pressure and will draw air in to re-inflate the air chambers. This mechanism automatically compensates for changes in load on top of the system.
ADVANTAGES OF HERZAN AIR-BASED ISOLATION
- Low profile
- Overall high level of performance
- Begins isolating in low frequencies (Onyx Series: 4 Hz)
- Large ballast tanks impart excellent stability to the system
- Available with manual and automatic load adjustment
- Offered in a range of sizes
- Customizable to meet specific research needs
- Exceptional value
- Unmatched cost-to-performance ratio