The Bently Nevada 21000-28-05-15-50-03-02, also cataloged as the 21000 series Proximity Probe Housing, operates as a dedicated hardware component for the mechanical positioning and environmental containment of eddy-current proximity probes within industrial machine casings.

Model Configuration Matrix

The 21000-28-05-15-50-03-02 part number defines the physical dimensions and interface specifications of the housing assembly. The configuration includes a 50 mm housing length, a 1/2-20 UNF probe thread interface, and a 1/2-inch NPT mounting thread. This hardware provides the necessary axial adjustment capability to position the transducer tip precisely relative to the monitored shaft, ensuring the mechanical reference remains stable during operation.

Hardware Specifications

Mechanical Monitoring & Eddy-Current Transduction

System integrity is contingent upon the mechanical rigidity of the transducer installation. The housing assembly supports accurate rotor dynamics monitoring by allowing for the adjustment of the probe tip gap. During commissioning, users must validate the -10 VDC gap voltage target to ensure the transducer system operates within its linear measurement range. Furthermore, cross-talk suppression must be addressed by ensuring adequate spacing between adjacent probes to prevent electromagnetic coupling between the high-frequency oscillators of nearby transducers.

## Ordering info

• 1x 21000-28-05-15-50-03-02 Probe Housing Assembly

• 1x Locking nut

• 1x O-ring seal

• 1x Installation instruction manual

Field Installation Guidelines

• Surface Preparation: The machine mounting boss must be machined square to the shaft centerline to prevent angular measurement inaccuracies.

• Thread Sealing: Apply industrial-grade thread sealant to the NPT interface if the application involves exposure to pressurized lubricants or process fluids.

• Positioning: Thread the housing into the mounting boss until the transducer tip achieves the target -10 VDC gap voltage at the shaft surface.

• Securing: Tighten the jam nut to 5.1 N-m (45 in-lb) to prevent mechanical vibration from altering the probe gap calibration during machine operation.

Frequently Asked Questions

• Does this housing include the proximity probe? No, the 21000 series housing is a passive mechanical component; the probe and extension cable are sourced as separate items.

• Can the housing be reused after removal? Yes, provided the threads are inspected for galling and the jam nut remains intact.

• What is the purpose of the 50 mm length? This length is specified to reach the appropriate depth in standard machine casing boss configurations.

• Can I replace the O-ring? Yes, the O-ring should be replaced whenever the housing is uninstalled to maintain the integrity of the seal against lubricant leakage.

• Is the housing compatible with all transducer series? It is designed for standard 8 mm probes; verify dimensional compatibility for specialized transducer configurations.

• How is cross-talk avoided? Ensure that multiple housings are not mounted in a way that allows the oscillating fields of the probe tips to overlap.

• What if the mounting boss is not perpendicular? Angular misalignment will cause non-linear signals; the mounting surface must be re-machined if the error is excessive.

• Is the housing stainless steel? The material is selected for resistance to industrial lubricants; confirm specific chemical compatibility if the machine uses non-standard synthetic oils.