Sometimes it is not possible to drill a hole into the structure, or the design of some accelerometers does not allow us to use stud mounting. In these cases, we can use an adhesive to secure the sensor to the monitored object.
Epoxy pads are also frequently used for permanent mounting of sensors where drilling and tapping are not permitted or possible. Properly installed epoxy pads can transmit high-frequency data (10 kHz or 600,000 CPM) very well and therefore can be used effectively for monitoring many gearbox and bearing faults. Avoid using them in cooling towers or other aggressive environments that could interfere with the bonding of the adhesive.
Figure 6. An example of using an adhesive mounting base to mount an accelerometer (image used courtesy of Condition Monitoring Analytics)
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MH130-1A — Mounting Disk with 1/4-28 Blind Tapped Hole, 1.0 in. (25.4 mm) Diameter — base/mounting pad that can be epoxied onto surface of the asset
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MH108-4B — 1/4-28 Mounting Stud, Stainless Steel, 0.5” (13 mm) Length
Note
Mounting stud is not needed with Erbessd Phantom wireless because Erbessd Phantom sensors are shipped with a stud installed
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Adhesive recommendations for adhesive mount:
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Purchased separately when ready to install
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Epoxy: Loctite AA330
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Activator: Loctite 7387
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The above is easy to apply, the attenuation is minimal, it is very forgiving and adheres to almost every surface. Our team has tried several other epoxies and the Loctite combo above is the best performance that the team has used.
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Industrial adhesives have a shelf life/expiration date. As with all adhesives, order what you need when you need it and be cognizant of ambient temperature for cure times.
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Choose a spot face diameter that has the same diameter as the surface of the sensor.
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Create a flat spot on the surface of the machinery. Apply even pressure to insure flatness. Surface should be as flat as practical.
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Clean the surface of the mounting location.
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Initial Cleaning:
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Remove loose debris: Use a brush or compressed air to clear dust and particles.
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Degrease: Wipe the surface with a lint-free cloth soaked in a solvent like isopropyl alcohol (IPA) or acetone to remove oils and grease.
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Surface Preparation:
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Smooth the surface: Use fine-grit sandpaper (e.g., 400–600 grit) or a Scotch-Brite pad to lightly abrade the surface. This increases surface area for better adhesion.
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Clean again: After abrasion, clean the surface again with IPA to remove any residue or particles.
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Apply a thin layer of Loctite 330 to the pad. Make sure the adhesive is compatible with all the environmental factors, including chemicals, moisture, and heat.
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Spray Loctite activator to the surface the pad is being adhered to.
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Hold the pad in place for 30 seconds.
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Tape the pad in place until the adhesive cures (see data Loctite 330 data sheet). Consider curing times of 3 to 6 hours, with 24 hours prior to applying any weight to the pad.
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Apply a thread locker such as Loctite 243 to the threads of the stud to prevent loosening from shock and vibration.
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Screw and tighten the sensor in place, tightening to a range of 2 to 5 foot-pounds (2.7 to 6.8 Nm).
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Paint any exposed metal on the surface of the machine to prevent corrosion.