Description

Configured for temporary seismic vibration sensor positioning and mechanical containment within machinery protection networks, the Bently Nevada 46920-01, also cataloged as the 46920-01 Velomitor Super Mag 100 Magnetic Base, provides direct physical/electrical execution. Specifically, this heavy-duty dual-rail magnetic coupling assembly mounts 330500 Velomitor piezo-velocity sensors directly to the flat, ferrous surface of industrial machine casings. Consequently, the high-adhesion adapter transfers dynamic casing velocity waveforms to the internal transducer element without requiring permanent structural drilling or tapped case holes. Furthermore, the specialized low-profile layout establishes a rigid mechanical connection that maintains high-frequency transmission during troubleshooting and periodic route-based asset diagnostics.

Hardware Specifications

Eddy-Current Probe Scaling and Mechanical Validation

Because this magnetic base establishes the physical coupling interface for seismic case-mounted sensors, its structural alignment directly affects measurement accuracy and system validation. Any micro-gaps, internal unflatness, or heavy paint scale beneath the magnetic interface weaken the flux loop, introducing high-frequency attenuation that skews the expected voltage throughput. Therefore, field technicians ensure structural cleanliness of the casing surface to preserve the calibrated sensor scaling factor and eliminate mechanical frequency dampening.

During transient machinery diagnostics or verification routines, asset engineers correlate casing data directly with proximity probe indicators. While proximity sensor circuits undergo precise gap voltage validation to maintain a stable -10 VDC baseline, casing velocity sensors rely entirely on the mechanical coupling stiffness of the Bently Nevada 46920-01 base to capture accurate high-frequency shell deflection. The 100 lbs nominal pull force counteracts local rotor dynamics and heavy case resonances, ensuring optimal cross-talk suppression between neighboring tracking channels. This high-force physical clamping suppresses base-rocking anomalies, preventing false harmonic modulation across the monitored frequency spectrum.

Frequently Asked Questions

Q: How does a non-ferrous paint layer on the machine casing alter the performance of the 46920-01 magnetic base?

A: Non-conductive industrial coatings act as a physical air gap, which decreases the total magnetic flux density and significantly reduces the rated 100 lbs holding force. Additionally, a thick, compliant paint layer absorbs high-frequency vibrations, causing the Velomitor to read lower velocity amplitudes than the actual casing level.

Q: Can you utilize this magnetic mount for permanent, continuous monitoring as part of a 3500 protection rack shutdown loop?

A: No, the design serves route-based data collectors and temporary diagnostic tracking. Over extended periods, constant thermal cycling and high case vibrations can cause the magnet to shift or gather microscopic environmental ferrous debris, which eventually degrades the acoustic coupling path.

Field Installation Guidelines

• Verify that the selected ferrous casing attachment zone is completely flat, unpainted, and clear of heavy oxidation or grease prior to placing the magnet down.
• Thread the Velomitor sensor stud completely into the 1/4-28 UNF center mounting port of the base, and tighten it manually using a wrench to the sensor manufacturer’s torque specification.
• Tilt the combined magnetic base onto the target surface starting from one edge rather than dropping it flat, which protects the internal piezoelectric elements of the attached sensor from high-G mechanical shock.
• Secure the sensor output cable to the surrounding framework using cable ties, ensuring the line maintains a minimum bend radius of 25.4 mm to prevent strain on the top connector.
• Ground the outer cable shield single-endedly at the monitor rack termination block, keeping the transducer and magnetic base isolated at the machine casing to eliminate common-mode ground loop noise.