Bently Nevada 330104-01-08-10-01-05 Proximity Probe – 3300 XL Series

Bently Nevada 330104-01-08-10-01-05: 8mm Eddy-Current Proximity Probe in the 3300 XL Machinery Protection Chain

The 330104-01-08-10-01-05 is an 8mm eddy-current proximity probe manufactured by Bently Nevada (Baker Hughes) for the 3300 XL measurement platform. Within a rotating machinery protection system, this probe functions as the primary displacement transducer — converting the physical gap between probe tip and shaft surface into a proportional DC voltage signal. That signal feeds downstream into a matched proximitor/signal conditioner, which in turn delivers a calibrated 0–10 V or 4–20 mA output to a DCS, safety PLC, or dedicated vibration monitor. The probe’s role is non-negotiable: without a correctly specified and calibrated sensing element, the entire measurement chain loses metrological traceability.

This part number encodes a precise mechanical and electrical configuration. The “8mm” designation defines the probe tip diameter, which directly governs the eddy-current field geometry and, consequently, the linear measurement range (0.25–2.25 mm). The “-05” suffix specifies a 5-metre integral cable — a factory-terminated coaxial assembly that eliminates any field-side connector joint between probe body and extension cable interface. Integral cable designs are preferred in high-vibration or high-temperature installations where connector joints introduce impedance discontinuities and ingress risk. The M10 × 1.0 thread allows direct installation into standard API 670 probe holders without adapter hardware.

Facilities operating Bently Nevada 3500 series rack monitors, System 1 condition monitoring software, or third-party vibration monitors with standard eddy-current inputs specify this part number for both OEM build-outs and direct field replacements. The probe is calibrated against AISI 4140 steel targets at the factory; installations involving non-ferrous shaft materials (Inconel, titanium, duplex stainless) require a documented target material correction factor applied at the proximitor or monitor level.

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Technical Parameters

Hardware Logical Analysis

The eddy-current measurement principle relies on the interaction between a high-frequency oscillating magnetic field (generated by the probe’s internal coil, typically driven at 1–2 MHz by the proximitor oscillator circuit) and the conductive target surface. As the gap between probe tip and shaft changes, the reflected impedance seen by the oscillator shifts proportionally. The proximitor demodulates this impedance change into a DC voltage output with a scale factor of 7.87 V/mm — a relationship that remains linear across the 0.25–2.25 mm range under standard target material conditions.

EMC Design: The coaxial cable geometry provides inherent shielding against radiated electromagnetic interference. The shield is grounded at the proximitor end only (single-point grounding), preventing ground loop currents that would appear as low-frequency noise on the displacement signal. In installations near variable-frequency drives or high-current bus bars, this single-point shield termination is the primary EMC mitigation mechanism. The probe body itself is constructed from corrosion-resistant stainless steel with a ceramic-filled epoxy tip, which is non-conductive and therefore transparent to the eddy-current field — ensuring the field geometry is determined solely by the coil winding, not the housing.

Integral Cable Impedance Matching: The 3300 XL system is calibrated as a matched three-component set: probe + extension cable + proximitor. The integral 5m cable is wound and terminated to a defined characteristic impedance. Substituting a non-matched cable length or cable type alters the total system capacitance, shifting the oscillator operating point and introducing a scale factor error that is not correctable by simple zero adjustment. This is why the “-05” suffix (5m integral cable) must be paired with an extension cable of the correct complementary length to reach the total system cable length specified on the proximitor label (typically 5m or 9m total).

Thermal Stability: The probe coil is wound on a thermally stable mandrel and potted with a compound rated to +121°C continuous. Thermal expansion of the probe body is accounted for in the M10 × 1.0 thread engagement length specification. In installations where the probe holder is subject to differential thermal expansion relative to the bearing housing (common in steam turbine applications), the probe’s axial position must be set at operating temperature or corrected via the proximitor’s DC gap adjustment.

System Integration Benefits

• Direct API 670 Compliance: The 330104-01-08-10-01-05 meets API 670 5th Edition requirements for proximity probe systems, eliminating the need for supplementary qualification testing during machinery protection system audits.
• Deterministic Signal Latency: The eddy-current measurement chain introduces no sampling delay — the output is a continuous analog signal. When interfaced to a 3500 series monitor, the overall system response time from shaft displacement to relay output is governed by the monitor’s voting logic, not the probe, enabling sub-10 ms trip response in critical protection applications.
• Diagnostic Transparency via Gap Voltage: The DC gap voltage (nominally −10 VDC at 1.0 mm) provides a continuous, observable diagnostic channel. Drift in gap voltage at steady-state operating conditions indicates probe fouling, shaft wear, or probe holder loosening — all detectable without removing the probe from service.
• Broadband Frequency Coverage: The DC to 10 kHz bandwidth captures sub-synchronous instabilities (oil whirl, surge), 1× and 2× synchronous components, and high-frequency blade-pass or gear-mesh events within a single measurement channel, reducing the number of transducers required per measurement plane.
• Non-Contact Operation: Zero mechanical loading on the shaft. The probe does not influence rotor dynamics, making it suitable for flexible rotor systems where added mass or stiffness from contact sensors would alter the critical speed map.
• Backward Compatibility with 3500 Infrastructure: The 3300 XL probe is electrically compatible with Bently Nevada 3500 series monitors and System 1 software without hardware modification, protecting existing monitor investments during probe replacement cycles.
• Contaminant Immunity: The eddy-current field penetrates oil films, process condensate, and non-conductive deposits without signal attenuation. This is a fundamental physical property of the measurement principle, not a coating or filter — making the probe inherently suitable for wet gas, lube oil mist, and steam environments.
• Standardized Spare Parts Inventory: The 330104-01-08-10-01-05 is the most widely deployed 8mm/5m configuration in the 3300 XL family. Stocking this single part number covers the majority of radial vibration measurement positions across a typical rotating equipment fleet, simplifying spare parts management and reducing carrying cost.

Quality Assurance & Global Logistics

Every 330104-01-08-10-01-05 unit offered through siemensplc.com is sourced as genuine Bently Nevada (Baker Hughes) hardware. Units are procured through verified supply channels with full part number and date code traceability. Prior to shipment from our Xiamen, China facility, each probe assembly undergoes a pre-shipment inspection covering physical integrity of the probe body and tip, coaxial cable continuity and shield integrity, connector seating and locking mechanism function, and label verification against the ordered part number. Original manufacturer packaging is preserved where available. A Certificate of Conformance (CoC) is available upon request for applications requiring documented quality records.

Logistics from Xiamen are structured for both speed and compliance. Standard air freight to major industrial hubs in Southeast Asia, the Middle East, Europe, and the Americas typically achieves 3–7 business day door-to-door transit. Expedited DHL/FedEx Priority options are available for emergency maintenance situations. Export documentation — including commercial invoice, packing list, and HS code classification — is prepared in compliance with Chinese customs regulations and destination country import requirements. DDP and DAP Incoterms are supported. For large-volume orders or project procurement, sea freight consolidation is available with extended lead time.

Contact Information

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