Product Core Brief
- Full Model: 330906-02-12-05-02-CN
- Brand: Bently Nevada (Baker Hughes)
- Series: 3300 XL NSv Compact Mini Eddy-Current Reverse Mount Proximity Transducer System
Full Suffix Decode
- 330906: Base NSv probe series
- Thread: 3/8-24 UNF American fine thread
- Installation type: Reverse Mount (backside rear counterbore mounting)
- Cable type: Factory integrated non-armored FEP coaxial cable
-02(A segment): Unthreaded smooth tip length = 0.2 inch (5.08 mm) PPS insulated sensing head-12(B segment): Stainless steel probe housing total length = 1.2 inch (30.48 mm) compact short body-05(C segment): Factory pre-attached signal cable length = 0.5 meter-02(D segment): Miniature gold-plated ClickLoc tool-free locking coaxial connector, standard FluidLoc oil-sealed molded joint-CN(E suffix): China special certification version, carries NEPSI domestic intrinsic safety explosion certification + ATEX/IECEx global Zone2 hazardous zone approvals, SIL2 functional safety rating
- Core Function: Miniature reverse-mount eddy-current proximity probe, installed from bearing housing rear counterbores where front mounting is mechanically blocked. Measures radial shaft vibration, axial thrust displacement and Keyphasor rotational speed signals for safety instrumented protection loops on small centrifugal compressors, aero-derivative gas turbines with narrow bearing housings.
- Product Type: One-piece factory integrated probe + non-armored 75Ω coaxial signal cable assembly
- Key Specs: 3/8-24 UNF reverse mount thread | 0.5m FEP non-armored cable | 7.87 V/mm (200 mV/mil) NSv standard linear sensitivity | FluidLoc anti-lube-oil infiltration molding | Dual domestic + international explosion-proof safety certifications
- Condition: New Original (New Surplus), active OEM petrochemical & power plant spare, no formal obsolescence schedule
Key Technical Specifications
| Parameter | Defined Value |
|---|---|
| Mounting Thread | 3/8-24 UNF standard American fine thread, rear reverse counterbore installation design |
| Unthreaded Tip Segment | 0.2 inch (5.08 mm) chemical-resistant PPS smooth sensing tip |
| Probe Stainless Steel Housing | 1.2 inch (30.48 mm) compact casing for shallow rear mounting holes |
| Factory Integrated Cable Length | 0.5 m matched 75Ω NSv coaxial cable |
| Cable Electrical Property | 75Ω low capacitance coaxial, FEP high-temperature oil-resistant outer jacket, no stainless steel armor |
| Sealing Technology | Patented FluidLoc molded probe-cable integrated joint, blocks turbine lube oil and process liquid wicking into internal conductors |
| Connector Hardware | Mini ClickLoc finger-lock gold-plated coaxial male connector, tool-free lock/unlock |
| Linear Measurement Range | 0.25 mm ~ 1.75 mm full linear span; factory recommended installation gap 1.0 mm (40 mil) mid-range |
| Standard NSv System Sensitivity | 7.87 V/mm (200 mV/mil) linear DC gap voltage output when matched with dedicated 330980 NSv Proximitor signal conditioner |
| Minimum Metallic Target Requirement | Flat target ≥8.9 mm diameter; minimum recommended monitoring shaft diameter ≥51 mm |
| Operating Temperature Range | Probe tip: −52°C ~ +177°C continuous; cable: −45°C ~ +100°C continuous cabinet operation |
| Mechanical Bend Limits | Static cable minimum bend radius 25.4 mm; dynamic vibration routing ≥50.8 mm |
| Axial Tensile Pull Strength | Max 330 N (75 lbf) without joint separation or internal wire breakage |
| Compliance & Certifications | API 670 4th Edition, CE EMC Class A, SIL2 functional safety; ATEX/IECEx Zone 2, CSA Div2, NEPSI China intrinsic safety explosion certification (unique CN suffix qualification) |
| System Hardware Compatibility | Exclusively matched with 3300 XL NSv series 75Ω Proximitor sensors (330980 series); analog output fully interoperable with all 3500 TSI rack monitor modules (3500/42M, 3500/50) |
| Mechanical Feature Distinction | Non-armored flexible FEP cable, lightweight for low-friction narrow cabinet routing |
Product Introduction
This compact reverse-mount NSv miniature proximity probe solves two core on-site installation pain points:
- Rear counterbore mounting limitation: Front mounting space blocked by shaft, mechanical seals or bearing structure, only rear-side installation available
- Ultra-narrow bearing housing ports: Standard large-body 8mm/11mm 3300 XL probes cannot fit, NSv mini series occupies minimal installation space
The FluidLoc molded integrated joint eliminates slow measurement drift caused by lubrication oil penetrating coaxial conductors, a major failure point of generic aftermarket replacement probes.
The -CN suffix variant is customized for Chinese refinery, LNG, chemical plant and thermal power hazardous classified zone projects, carrying both international ATEX/IECEx and domestic NEPSI explosion-proof certifications, fully compliant with China’s local explosion safety inspection standards, replacing the standard -05 multi-cert export-only model for domestic bidding and site acceptance.
Complete NSv Measurement System Composition
NSv Reverse Mount Mini Probe (330906 series) + optional matching NSv extension cable + dedicated 330980 NSv Proximitor signal conditioner + 3500 series TSI rack monitor
Critical Compatibility Limitation
This NSv probe uses 75Ω coaxial impedance, completely incompatible with standard 50Ω triaxial 8mm/11mm 3300 XL probe front ends (330180 series). Cross-mixing hardware will destroy linearity and produce severe permanent measurement offset errors.
Model Series Distinction (NSv Reverse Mount)
- 330906: 3/8-24 UNF thread, non-armored NSv reverse mount probe (this model)
- 330907: 3/8-24 UNF thread, armored NSv reverse mount probe
- 330910: M10×1 metric thread, armored NSv reverse mount probeAll NSv series share identical 75Ω electrical matching, interchangeable within the full NSv system.
Firmware & Software Compatibility Notes
This probe is a passive analog sensing assembly with no onboard firmware. System matching rules for paired NSv Proximitor and 3500 TSI rack monitors:
- Minimum compatible 3500 monitor firmware revision: Revision G
- Minimum Rack Configuration Software version: v2.00
- All M-series monitor modules inside the 3500/05 chassis must run unified matching firmware revisions to correctly interpret the NSv 200 mV/mil linear gap voltage characteristic curve.
- Mandatory commissioning step: Input total combined transducer length (0.5m probe + optional extension cable) into rack configuration software to activate built-in cable capacitance linearity compensation; incorrect length input generates permanent static measurement offset errors.
Frequently Asked Questions
- Can I disconnect the NSv probe ClickLoc connector while the NSv Proximitor 24VDC power remains live?Yes, power shutdown is not required for connector disconnection. Unplugging the RF input triggers persistent channel fault alarms on the 3500 rack and cuts all vibration/thrust displacement data, but no permanent damage occurs to the Proximitor internal circuit or rack monitor analog input. Fully re-seat the ClickLoc connector until the locking tab clicks to clear fault status.
- Is this part obsolete? Are there direct plug-and-play alternative variants?This compact NSv reverse mount probe remains active OEM stock with no end-of-life date:
- General industrial non-hazardous version: 330906-02-12-05-02-00 (no explosion certifications, cannot be deployed in classified zones)
- Global export multi-cert version: 330906-02-12-05-02-05 (ATEX/IECEx/CSA only, without Chinese NEPSI, fails domestic hazardous zone site inspection)The
-CNversion is uniquely qualified for Chinese explosion classified safety instrumented loops and cannot be zero-modification interchanged with-00/-05for domestic refinery/chemical plant projects.
- Will transducer linearity or gap calibration data erase if the rack loses full power?All NSv system length and sensitivity calibration parameters store in non-volatile flash memory on the paired 3500 monitor module, not the probe assembly itself. Full rack power loss does not erase transducer configuration data; swapping this unit only requires physical reconnection with zero software rework if total transducer length stays unchanged.
- What warranty and reliability differences separate New Surplus original vs refurbished units?New Surplus factory original probes carry a 12-month full functional warranty covering coil linearity, 75Ω coaxial impedance consistency, ClickLoc connector plating integrity, FluidLoc molded seal performance, and full NEPSI/ATEX certification validity. Refurbished probes only offer 3–6 month limited coverage, with hidden risks of cracked PPS tip insulation, worn connector locking tabs, and compromised liquid sealing that cause drifting vibration readings during turbine thermal load cycles.
- Why is New Surplus original pricing higher than generic used/refurbished alternatives?All brand-new original probes pass complete standardized factory QC validation: serial traceability against OEM production logs, full 0–1.75mm linearity sweep bench testing, 24-hour thermal soak aging test, RF input impedance matching verification, 1000-cycle connector lock durability testing, and sealed anti-static factory packaging with full dual certification documentation. Refurbished units skip this multi-step electrical and mechanical testing workflow, introducing unplanned downtime risk for safety-critical compressor vibration and thrust position protection loops.
- Can this NSv reverse mount probe mate with standard 330180 series 8mm XL Proximitor sensors?No, this NSv probe uses 75Ω coaxial matching parameters exclusive to 330980 NSv dedicated front ends. Standard 8mm XL probe systems adopt 50Ω triaxial cables with different capacitance matching parameters; cross-mixing hardware completely breaks measurement linearity and generates severe permanent offset errors. Verify NSv vs standard XL impedance before wiring to avoid irreparable Proximitor RF input circuit damage.
- Does the probe locally store vibration waveforms or long-term rotor position trending logs?No, the assembly is a fully passive analog sensing component with zero memory or signal processing hardware. All vibration amplitude, axial thrust displacement, Keyphasor rotational speed trending records and fault event logs are captured and retained exclusively by the Slot1 3500/20 TDI master communication gateway module. This probe only outputs raw high-frequency eddy-current gap voltage signals without modifying or storing measurement data.
