Bently Nevada 130938-04-10-01 Proximity Probe – 3300 XL Series

Bently Nevada 130938-04-10-01: Non-Contact Shaft Measurement in Rotating Machinery Protection Systems

The Bently Nevada 130938-04-10-01 is an 8 mm eddy current proximity probe forming the primary sensing element of the 3300 XL Proximity Transducer System. Its function within a machinery protection loop is unambiguous: it converts the physical gap between probe tip and rotating shaft surface into a calibrated DC voltage signal, providing the monitor rack with continuous, real-time data on radial vibration amplitude, shaft centerline position, and axial thrust displacement. In turbine, compressor, and pump protection architectures governed by API 670, this probe is the first link in the measurement chain — and its dimensional accuracy, thermal stability, and signal linearity directly determine the integrity of every downstream alarm and trip decision.

Unlike contact-type sensors, the eddy current principle requires no mechanical coupling to the target. The probe tip generates a high-frequency oscillating electromagnetic field (typically 1 MHz carrier). When a conductive target enters this field, eddy currents are induced on the target surface, loading the oscillator circuit and producing a measurable impedance change. The driver/oscillator demodulates this impedance shift into a DC output voltage proportional to gap distance. For the 130938-04-10-01 calibrated against AISI 4140 steel, the transfer function is linear across the 0.25 mm to 2.25 mm gap range at a nominal sensitivity of 7.87 V/mm (200 mV/mil). This linearity is not incidental — it is the result of factory calibration pairing between probe, extension cable, and driver as a matched system, a requirement explicitly defined in API 670 Section 5.

The -04-10-01 suffix encodes three critical configuration parameters: -04 designates a 1.0 m integral armored cable; -10 specifies M10 × 1 metric thread for probe body mounting; -01 identifies the standard coaxial connector interface. Procurement engineers replacing existing transducers must verify all three suffix fields against the original system drawing before substitution, as cable length directly affects the driver calibration range and total system sensitivity.

From Xiamen, China, siemensplc.com maintains verified stock of the 130938-04-10-01 with full traceability documentation. Each unit undergoes physical inspection — connector integrity, cable continuity, and tip condition — prior to dispatch. OEM calibration certificates and chain-of-custody records are available for critical applications in nuclear, offshore, and regulated petrochemical facilities. International shipments are processed via DHL and FedEx Express with complete export documentation including commercial invoice, packing list, and certificate of origin for seamless customs clearance.

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

Technical Parameters

Hardware Logical Analysis

Oscillator Loading and Gap-to-Voltage Transfer Function
The probe coil, extension cable, and driver oscillator form a resonant LC circuit. As the conductive target approaches the probe tip, induced eddy currents on the target surface dissipate energy from the oscillator, reducing oscillation amplitude. The driver demodulates this amplitude change and outputs a negative DC voltage linearly proportional to gap distance. The 130938-04-10-01 is factory-matched to its driver at a defined total cable length — altering cable length without recalibration shifts the resonant frequency of the LC circuit and introduces a systematic sensitivity error that cannot be corrected at the monitor level.

PEEK Tip Encapsulation and EMC Isolation
The probe tip is encapsulated in PEEK (polyether ether ketone), a semi-crystalline thermoplastic with a dielectric constant of approximately 3.2 and a continuous service temperature exceeding 250°C. PEEK provides electrical isolation between the coil winding and the metallic probe body, preventing ground loop currents that would appear as low-frequency noise on the output signal. In high-EMI environments — such as variable-frequency drive (VFD) motor rooms or switchgear enclosures — this isolation is the primary defense against common-mode interference coupling into the measurement signal.

Armored Integral Cable and Triaxial Shielding
The 1.0 m integral cable uses a triaxial construction: inner conductor (signal), inner shield (driven guard), and outer shield (ground). The driven guard, held at the same potential as the signal conductor by the driver’s buffer amplifier, eliminates capacitive leakage between signal and outer shield across the cable length. This is particularly significant in long cable runs where cable capacitance would otherwise attenuate high-frequency vibration components above 1 kHz, degrading the probe’s effective bandwidth below its rated 10 kHz specification.

Target Material Sensitivity Correction
Eddy current depth of penetration (skin depth δ) is a function of target material resistivity (ρ), permeability (μ), and excitation frequency (f): δ = √(ρ / πfμ). For non-standard target materials such as Inconel 718 (higher resistivity) or 17-4 PH stainless steel (variable permeability), the effective sensitivity deviates from the AISI 4140 baseline by up to ±15%. Bently Nevada publishes material correction factors for common alloys; these must be applied as a scale factor in the monitor configuration to maintain measurement accuracy within API 670 tolerances.

System Integration Benefits

• Zero-wear continuous measurement: Non-contact eddy current principle eliminates mechanical degradation of the sensing element, enabling indefinite service life in clean bearing environments without scheduled probe replacement intervals.
• DC-to-10 kHz bandwidth: The flat frequency response from DC captures slow-roll runout and thermal bow at startup, while the 10 kHz upper limit resolves sub-synchronous instabilities, blade-pass frequencies, and gear mesh harmonics in a single measurement channel.
• API 670 plug-and-play compatibility: Factory calibration to the 3300 XL system standard means the 130938-04-10-01 installs into existing monitor racks without sensitivity rescaling, reducing commissioning time and eliminating calibration-related loop errors.
• High-temperature operational envelope: The +177°C upper limit allows direct installation at turbine bearing pedestals and hot-section compressor housings without thermal standoffs or remote mounting brackets, reducing installation complexity and potential signal path length errors.
• IP67 ingress protection: The probe body withstands oil mist, process condensate, and high-pressure wash-down, maintaining measurement integrity in wet or contaminated bearing environments without additional protective enclosures.
• Deterministic signal latency: The analog DC output signal from the driver reaches the monitor with propagation delay determined only by cable length — no digital sampling jitter, no protocol overhead. This determinism is essential for machinery protection systems where trip response time is specified in milliseconds.
• Diagnostic transparency via gap voltage monitoring: The –24 VDC output provides a direct, continuously readable gap voltage that maintenance engineers can measure with a standard voltmeter at the monitor terminal strip, enabling rapid field verification of probe installation gap without specialized test equipment.
• Redundant system architecture support: The 3300 XL platform supports dual-probe redundant configurations on a single monitor channel. The 130938-04-10-01’s matched sensitivity ensures both probes in a redundant pair produce identical transfer functions, preventing false differential alarms during normal operation.
• Compatibility with 3500 series monitors: The standard –24 VDC output is accepted by Bently Nevada 3500 series monitor cards without signal conditioning adapters, providing a forward-compatible upgrade path when migrating from 3300 XL to 3500 rack infrastructure.
• Serialized traceability: Each probe carries a serial number traceable to Bently Nevada manufacturing records, supporting asset management systems and regulatory audit requirements in nuclear and offshore applications.

Quality Assurance & Global Logistics

Every 130938-04-10-01 unit supplied by siemensplc.com is sourced through verified industrial automation distribution channels with documented chain of custody. Pre-shipment inspection covers probe tip physical condition, integral cable continuity and insulation resistance, connector pin integrity, and housing surface condition. OEM calibration certificates issued by Bently Nevada are available upon request for units requiring documented traceability to a NIST-traceable calibration standard — a common requirement for machinery protection systems in regulated industries.

Shipments originate from Xiamen, China, a major international logistics hub with direct access to DHL, FedEx, and UPS express networks. Standard international transit times are 3–5 business days to Europe, 4–6 business days to North America, and 2–4 business days to Southeast Asia. Each shipment includes a commercial invoice, detailed packing list, and certificate of origin to support import customs clearance in all major markets. For time-critical plant maintenance scenarios, same-day dispatch is available for in-stock units when orders are confirmed before 14:00 CST.

All units are covered by a 12-month warranty from the date of shipment against manufacturing defects and functional failure under normal operating conditions. Technical support for installation gap setting, signal verification, and system commissioning is available via email and WhatsApp throughout the warranty period and beyond.

Contact Information

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