VIB-ISO-BASE: Vibration Isolation Rack for SIRIUS and SBOX Waterproof

Introduction

Machines with moving parts normally produce some form of vibration. Usually, these vibrations have lower magnitudes which don’t affect the lifetime of electronics in measurement instruments. However, on machines that produce vibrations of higher magnitudes during operation (pneumatic hammers, vibratory separators…) the lifetime of electronics can be significantly reduced. Without a considerable redesign of electronics, instruments can only be used in such environments if the electronic boards are enclosed in rubber or are isolated from the outside vibration by some form of a damping system.

Isolation mount 

We opted for the second option – isolating SIRIUS waterproof data acquisition systems from outside vibration. We developed a mounting mechanism that isolates the instruments by suspending them on four rubber dampers. The mounting mechanism was finalized after three testing-redesign iterations.

Mounts were tested under a random vibration specified by the power spectral density (PSD).

Tests were performed on an in-house shaker, covering all three directions. The isolation effectivity was evaluated by acceleration measurements on the instruments and different parts of the mount. A SIRIUS DAQ system with ACC amplifiers acquired the data, calculating the Dewesoft Modal Test mathematics in real-time. In this way, the isolation performance was evaluated in a couple of minutes.

The VIB-ISO-BASE has a low natural frequency, where the excitation vibrations are amplified (around 30 Hz depending on the excitation direction). All of the vibration frequencies higher than that are dampened by the mount. It is especially effective at higher frequencies which are more harmful to electronic components. The instrument acceleration amplitudes are at least fourteen times lower than the excitation amplitudes at frequencies above 1000 Hz.

The durability of the mounts and instruments was also tested in all three directions, while continuously storing measurement data.

Instrument rack

The developed isolation mounts were incorporated in a robust instrument rack that can house SIRIUS waterproof or SBOX waterproof instruments. The instrument rack can successfully sustain the vibrations in any direction, it provides the same isolation to the units as the developed isolation mount.

The VIB-ISO-BASE rack can house one or two instruments and can be extended to house up to four SIRIUSwe instruments by using the VIB-ISO-EXTENDER. The rack is bolted or strapped to remain fixed.

VIB-ISO and VIB-ISO-EXTENDER are now available to buy as an accessory to the SIRIUSwe line of data acquisition instruments.