Increases centers between isolators for added stability. There are a variety of isolators available. It depends on circumstances peculiar to the installation. The following chart lists the basic isolator types available, namely elastomeric, steel and air spring. Air isolators yield the lowest natural frequency.
Steel is next then elastomers.
There are other materials available such as felt, cork, fabric and wool, which are used when a stiffer isolator is required. In most cases, an isolator is selected on the basis of natural frequency requirements to give the isolation desired. Isolation desired - percent reduction Lowest disturbing frequency Maximum load per isolator, weight distribution, location of c.g. The following example will serve to illustrate and summarize the above. An industrial fan is transmitting vibration into its elevated floor support so that it is being felt by personnel in an office on this same floor.