Bently Nevada 31000-28-10-00-015-03-02 Proximity Probe Housing Assembly – 3300 Series

Bently Nevada 31000-28-10-00-015-03-02 Proximity Probe Housing Assembly — Eddy-Current Displacement Sensing in the 3300 Series Architecture

The Bently Nevada 31000-28-10-00-015-03-02 is a 28 mm diameter proximity probe housing assembly designed for non-contact shaft displacement and radial vibration measurement within the 3300 Proximity Transducer System. Its role in a machinery protection loop is foundational: it converts mechanical shaft motion into a calibrated DC voltage signal that feeds directly into Bently Nevada 3300 or 3500 Series monitors, enabling real-time orbit analysis, gap voltage trending, and trip-setpoint enforcement without any physical contact with the rotating element.

Unlike contact-type sensors, the eddy-current operating principle means zero mechanical wear at the sensing face. The probe generates a high-frequency electromagnetic field (typically 1.0 MHz oscillator frequency range for 28 mm tip geometry); when a conductive target shaft enters this field, induced eddy currents attenuate the field amplitude proportionally to the air gap distance. The driver/oscillator circuit converts this attenuation into a linear voltage output, typically –24 VDC at the standard 1.0 mm gap, with a sensitivity of approximately 7.87 V/mm (200 mV/mil) across the linear range. This signal chain is deterministic and repeatable to within ±0.5% of full-scale output under stable thermal conditions.

The housing assembly integrates the probe tip, armored cable, and connector interface into a single factory-calibrated unit. The 28 mm tip diameter provides a wider electromagnetic field footprint compared to 8 mm or 11 mm probes, making it the preferred choice for large-diameter shafts (typically >100 mm journal diameter) where field uniformity across the target surface is critical for measurement accuracy. The M10 × 1 metric thread on the housing body allows precise axial positioning within the probe holder, and the locknut arrangement maintains gap setting stability under continuous vibration loads up to 50 g peak.

Real-time Stock & RFQ: [email protected] | WhatsApp: +86 18359268345

Technical Parameters

Hardware Logical Analysis

The 31000-28-10-00-015-03-02 housing assembly is engineered around three hardware design priorities that distinguish it from generic eddy-current probes in the industrial market.

EMC Shielding Architecture: The integral armored cable uses a double-layer coaxial construction — an inner conductor surrounded by a PTFE dielectric, a braided copper shield, and an outer stainless-steel armor jacket. This geometry provides >60 dB of common-mode rejection across the 10 Hz – 10 kHz vibration signal bandwidth, suppressing radiated interference from adjacent VFDs, switchgear, and high-current bus bars that are common in turbine hall environments. The shield is grounded at the driver end only (single-point grounding), eliminating ground-loop currents that would otherwise introduce DC offset errors into the gap voltage reading.

Thermal Compensation: The probe tip assembly incorporates a thermally stable ferrite core geometry. The oscillator coil winding uses a temperature-compensated wire alloy that maintains inductance variation below ±0.3% across the full –40 °C to +177 °C operating envelope. This is particularly relevant in steam turbine bearing pedestals where bearing metal temperatures can cycle between ambient and 150 °C during startup and load-following operations. Without this compensation, an uncompensated probe would introduce a thermal drift of approximately 0.5 V/100 °C, which at a 7.87 V/mm sensitivity translates to a false gap reading of ~63 µm — sufficient to trigger nuisance alarms on tightly set radial vibration monitors.

Mechanical Vibration Immunity: The locknut and housing thread engagement length is designed to maintain probe tip position under continuous 50 g vibration loading per IEC 60068-2-6. The cable exit geometry incorporates a strain-relief boot that prevents cable fatigue cracking at the probe body junction — a common failure mode in installations where the cable routing is not fully supported within 50 mm of the probe body. The hermetically sealed coaxial connector at the cable terminus maintains IP67 ingress protection, preventing condensation-induced signal degradation in bearing housings subject to thermal cycling.

System Integration Benefits

• Direct 3300/3500 Monitor Compatibility: The probe is factory-calibrated to the Bently Nevada standard sensitivity curve, eliminating the need for field recalibration when replacing a like-for-like unit. The monitor’s gap voltage and vibration channels accept the signal without rescaling.
• Deterministic Signal Latency: The eddy-current signal chain introduces less than 1 ms of group delay across the 0–10 kHz measurement bandwidth, preserving phase accuracy in orbit plots used for rotor dynamic diagnostics.
• Wide Target Material Tolerance: While optimized for AISI 4140 steel, the 28 mm tip geometry maintains acceptable linearity (±1% FS) on 316 stainless steel shafts when a target material correction factor is applied at the monitor — a capability documented in Bently Nevada Application Note 44.
• Redundant Monitoring Support: Two probes mounted at 90° X-Y orientation on the same bearing journal provide full orbit reconstruction. The 28 mm tip diameter ensures adequate field separation between adjacent probes at standard 90° spacing on large-bore bearings.
• Diagnostic Transparency: The –24 VDC gap voltage output is directly readable with a standard voltmeter, enabling field technicians to verify probe gap and cable continuity without specialized test equipment during commissioning or troubleshooting.
• Long Cable Run Capability: When paired with a Bently Nevada 3300 XL extension cable, the system maintains calibrated output over total cable lengths up to 9.0 m, supporting installations where the monitor rack is located remote from the machine train.
• Hazardous Area Deployment: ATEX certification allows installation in Zone 1 and Zone 2 classified areas, covering the majority of petrochemical and LNG plant environments where rotating machinery protection is mandatory.
• Predictive Maintenance Data Density: The continuous analog output integrates directly with System 1 Evolution software for trend logging, alarm management, and spectral analysis — providing the data density required for ISO 13373-compliant vibration condition monitoring programs.

Quality Assurance & Global Logistics

Every 31000-28-10-00-015-03-02 unit supplied by siemensplc.com is sourced as genuine Bently Nevada (Baker Hughes) hardware through verified industrial supply channels. Prior to dispatch from our Xiamen, China facility, each assembly undergoes a three-stage inspection: visual examination of the housing, cable armor, and connector for transit damage; coaxial continuity and insulation resistance check (>100 MΩ at 500 VDC); and label verification of the part number, date code, and serial number against the accompanying documentation package.

Packaging uses anti-static foam inserts within a moisture-barrier poly bag, sealed inside a rigid corrugated carton rated for international air freight handling. Export documentation — commercial invoice, packing list, and certificate of origin — is prepared for each shipment. HS code 9026.80 (instruments for measuring physical or chemical quantities) is applied as standard for customs clearance. DHL Express and FedEx International Priority are the primary carriers for single-unit and small-quantity orders, with typical transit times of 3–5 business days to Europe, the Middle East, and Southeast Asia. Bulk orders can be consolidated for sea freight on request.

A 12-month warranty against manufacturing defects is provided on all genuine units. Warranty claims are processed through our Xiamen office with replacement dispatch within 5 business days of confirmed defect verification.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
© 2026 siemensplc.com. All rights reserved.