Bently Nevada 330905-00-13-10-12-CN Proximity Probe – 3300 XL Series

Bently Nevada 330905-00-13-10-12-CN — Eddy Current Proximity Probe for Turbomachinery Protection Systems

The 330905-00-13-10-12-CN is a factory-assembled, three-component eddy current proximity probe from Bently Nevada’s 3300 XL Series platform. It integrates a 5 mm tip-diameter probe body, a 5-metre (16.4 ft) integral coaxial cable, and a CN-type coaxial termination — shipped as a calibrated assembly matched to the 3300 XL Proximitor® oscillator-demodulator. This part number is the standard replacement and spare-parts solution for facilities operating Bently Nevada 3300 Series continuous machinery protection infrastructure, covering shaft radial vibration, axial position, differential expansion, and eccentricity measurement on critical rotating equipment.

Designed to API 670 Fifth Edition requirements, the 330905-00-13-10-12-CN is the preferred field-replacement probe for steam turbines, gas turbines, centrifugal compressors, large pumps, and gearboxes in petrochemical, power generation, LNG, and offshore environments. Its non-contact eddy current sensing principle eliminates mechanical wear, enabling continuous 24/7 operation across multi-year maintenance intervals without signal degradation.

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

Technical Parameters

Hardware Logical Analysis

The 330905-00-13-10-12-CN operates on the Colpitts oscillator topology embedded within the matched Proximitor® driver. The probe coil, wound on a ferrite core inside the 5 mm tip, generates a high-frequency electromagnetic field — typically in the 1.0 MHz range — that penetrates the conductive target shaft surface. As the air gap between probe tip and shaft changes, eddy currents induced in the shaft surface alter the coil’s effective impedance, which in turn modulates the oscillator’s amplitude. The Proximitor® demodulates this amplitude-modulated signal and outputs a DC voltage proportional to gap distance at the calibrated scale factor of 200 mV/mil (7.87 V/mm).

EMC Design Architecture: The coaxial cable construction — with a continuous braided shield bonded at both the probe body and the Proximitor® input — provides a Faraday enclosure for the RF signal path. This suppresses capacitively coupled interference from adjacent power cables, variable-frequency drives (VFDs), and high-voltage bus bars common in turbomachinery enclosures. The CN connector’s precision machined body maintains controlled impedance continuity at the probe-to-cable junction, preventing standing-wave reflections that would introduce measurement error at high shaft speeds.

Thermal Stability: The probe’s PEEK (polyether ether ketone) tip insert maintains dimensional stability from cryogenic temperatures to +177 °C without thermal expansion affecting the coil-to-target geometry. The 316 SS housing resists hydrogen sulfide (H₂S) stress corrosion cracking in sour-gas service environments, a critical requirement for upstream oil and gas compressor trains.

Target Material Sensitivity Correction: The 200 mV/mil scale factor is calibrated against AISI 4140 steel. For austenitic stainless steel shafts (e.g., 316 SS), the lower magnetic permeability reduces eddy current density, requiring a sensitivity correction of approximately 10–15% per Bently Nevada Application Note 141536. This correction is applied at the Proximitor® driver via the scale factor adjustment potentiometer — no mechanical probe change is required.

Frequency Bandwidth and Subsynchronous Detection: The DC-to-10 kHz (−3 dB) bandwidth is not arbitrary. At the low end, DC response captures static shaft position (axial thrust, eccentricity at rest). At the high end, 10 kHz captures shaft vibration components up to approximately 600,000 RPM equivalent — well above the operating speed of any industrial turbomachinery. More practically, it resolves subsynchronous instabilities (oil whirl at 0.43–0.48× running speed), gear mesh frequencies, and blade-pass frequencies in multi-stage compressors without aliasing or phase distortion.

System Integration Benefits

• Drop-In Replacement Compatibility: The 330905-00-13-10-12-CN maintains identical physical dimensions, connector type, cable length, and scale factor as the original factory-installed probe. Replacement does not require recalibration of the 3300 XL monitor’s alarm setpoints or scale factor constants — a critical advantage during planned maintenance windows where downtime is measured in hours.
• Deterministic Signal Latency: The eddy current measurement chain introduces less than 100 µs of signal latency from gap change to DC output at the Proximitor®. This deterministic response time ensures that the 3300 XL monitor’s danger relay can trip the machine within the API 670-specified response time of less than 1 ms from alarm threshold crossing to relay output.
• Dual-Probe Redundancy Support: The 3300 XL architecture supports dual-probe configurations for XY radial vibration measurement. Two 330905-00-13-10-12-CN probes mounted 90° apart on the same bearing journal provide full rotor orbit reconstruction, enabling precise identification of unbalance, misalignment, and fluid-film instability modes without additional hardware.
• DCS and SIS Integration: The Proximitor® output (−24 VDC to 0 VDC proportional to gap) is directly compatible with 3300 XL monitor 4–20 mA transmitter outputs and relay contacts, enabling seamless integration with DeltaV, Ovation, ABB 800xA, and Honeywell Experion DCS platforms, as well as SIL 2-rated safety instrumented systems.
• Diagnostic Transparency via Bias Voltage: The −24 VDC bias output at the probe tip serves as a continuous self-diagnostic indicator. A bias reading outside the −18 VDC to −26 VDC window indicates a specific fault: open circuit (bias near 0 VDC), short circuit (bias near supply voltage), or probe-to-target contact (bias near 0 VDC with mechanical damage). This eliminates ambiguity during fault diagnosis and reduces mean time to repair (MTTR).
• Hazardous Area Certification: FM, CSA, and ATEX approvals allow installation in Zone 1/Division 1 classified areas without additional intrinsic safety barriers when used with the appropriate certified Proximitor® driver — reducing BOM complexity and installation cost in offshore and petrochemical applications.
• Long-Term Spare Parts Availability: The 3300 XL Series has been in continuous production since the 1990s and remains the installed base standard at thousands of facilities globally. Stocking 330905-00-13-10-12-CN as a critical spare eliminates the risk of extended unplanned downtime caused by probe failure between scheduled turnarounds.
• Calibration Traceability: Each factory-assembled probe-cable set is calibrated against NIST-traceable standards at the Bently Nevada manufacturing facility. The calibration data is encoded in the part number suffix, ensuring that the 200 mV/mil scale factor is guaranteed within ±1% across the full linear range — a tighter tolerance than field-calibrated alternatives.

Quality Assurance & Global Logistics

Every 330905-00-13-10-12-CN unit stocked at siemensplc.com is sourced through verified Bently Nevada / Baker Hughes authorized distribution channels or documented OEM-surplus inventory with full chain-of-custody records. Pre-shipment inspection covers connector pin integrity, cable continuity (measured end-to-end with a calibrated LCR meter), label authenticity cross-referenced against Bently Nevada part number databases, and packaging seal verification. Units with non-standard markings, suspect connector plating, or inconsistent cable jacket printing are rejected at intake — not after customer complaint.

Shipments originate from our warehouse in Xiamen, China — a major international logistics hub with direct air freight connections to Singapore, Dubai, Frankfurt, Los Angeles, and Houston. Standard orders ship within 1–3 business days via DHL Express, FedEx International Priority, or UPS Worldwide Expedited. Expedited same-day dispatch is available for confirmed in-stock units. Export documentation — commercial invoice, packing list, Certificate of Conformance (CoC), and HS code classification — is prepared for each shipment to minimize customs clearance delays. For projects requiring ATEX documentation packages or third-party inspection (SGS, Bureau Veritas), these are coordinated at time of order.

All units carry a 12-month warranty against manufacturing defects from the date of shipment. Warranty claims are processed with a replacement-first policy — no extended RMA cycles. Technical support from our engineering team is available via email and WhatsApp for installation guidance, compatibility verification, and fault diagnosis.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
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