This document focuses on wireless accelerometer installation techniques. It includes stud mounting, adhesive mounting, and magnetic mounting. The document describes the tools and materials required, and best practices for sensor location.
There are four objectives when mounting accelerometers:
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Minimize the mass (weight) added to the machine
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Maximize the surface area contact between the accelerometer and the machine
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Maximize stiffness of the mount
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Locate the sensor mount close to the source of vibration (bearing housing)
Stud mounting and adhesive mounting provide the best repeatability of vibration data collection. Both techniques provide higher frequency ranges, often to the full useful range of the sensor. However, adhesive and stud mounting require more time and care compared to magnetic mounting.
Proper permanent installation of vibration sensors will maximize frequency response, maximize data quality, and ensure long-term adhesion to the machine. To ensure long-term, it is necessary to use proper surface preparation and use materials compatible with the machinery environment.
Vibration sensors should be mounted on the bearing housing, or as closely as possible and oriented in a horizontal, vertical, or axial direction. The top-dead-center position is preferred for permanent online monitoring. Locations with high temperature variations or significant air flow velocities should be avoided if possible. See Figure 1, “Mounting location priority (image courtesy of STI Vibration Monitoring)” for location orientation. For triaxial accelerometers, the vertical position is preferred.
Figure 2. Triaxial sensors mounted in the horizontal position of a horizontally oriented motor and vertically on a vertically oriented motor
Figure 3. Triaxial sensors mounted in the vertical position of the motor and input bearing of the pump
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Figure 4, “Common Tools for accelerometer mounting (image used courtesy of Connection Technology Center, Inc.)” depicts common tools used for accelerometer mounting.
For adhesive mounting, a spot facing tool, file, and wire brush are useful along with (not shown) fine-grit sandpaper (e.g., 400–600 grit) or a Scotch-Brite pad to lightly abrade the surface. Additionally, lint-free cloth soaked in a solvent like isopropyl alcohol (IPA) or acetone to remove oils and grease.
When stud mounting, additional tools are used including a pilot drill bit, taps, tap handle, and center punch. Stud mounting is the preferred method.
Figure 4. Common Tools for accelerometer mounting (image used courtesy of Connection Technology Center, Inc.)