Bently Nevada 3300 Series Proximity Probes

Technical Dossier

Product Details And Specifications

Bently Nevada 3300 Series: Comprehensive Proximity Probe Range and Technical Overview

The Bently Nevada 3300 Series is the global standard for eddy-current proximity measurement in rotating machinery protection systems. Deployed across petrochemical refineries, nuclear power stations, LNG terminals, offshore platforms, and heavy industrial compressor trains, the 3300 Series forms the sensing layer of the Bently Nevada 3500 and 7200 Series rack-based machinery protection systems. Its non-contact measurement principle — based on the eddy-current effect — delivers continuous shaft position, vibration amplitude, and differential expansion data with sub-micron resolution. The series is fully compliant with API 670 (5th Edition) machinery protection standards, making it the default specification in EPC contracts for rotating equipment worldwide. Installed base estimates exceed several million probe assemblies globally, with active deployments spanning 30+ years of continuous operation in safety-critical environments.

The Evolution of 3300 Series Architecture

The 3300 Series was introduced by Bently Nevada Corporation (acquired by GE in 2002, subsequently integrated into Baker Hughes in 2017) as a modular, field-configurable proximity transducer system. The architecture is built on a three-component assembly: the probe tip (eddy-current sensing element), the extension cable (coaxial, impedance-matched), and the proximitor sensor (signal conditioning oscillator/demodulator). This triaxial architecture allows field replacement of individual components without disturbing the full assembly, a critical advantage in continuous-process industries where planned shutdowns are measured in years.

Early 3300 Series variants (pre-2000) used 5-meter and 9-meter standard cable configurations with BNC-terminated coaxial connections. Post-2002 GE-era revisions standardized on the 330130 Proximitor housing format and introduced the XL (Extended Length) probe variants for deep-bore installations. The 330103 sub-series specifically addresses standard radial vibration and axial position measurement with a 5mm probe tip diameter and a linear measurement range of 0–2.54 mm (0–100 mil). Compatibility with legacy 3300 Series racks (3300/16, 3300/20, 3300/25) and the current 3500 Series monitors is maintained through consistent output signal specifications: -24 VDC supply, output range -1 to -17 VDC, scale factor 7.87 V/mm (200 mV/mil). The series entered its maturity/lifecycle-extension phase circa 2015, with Bently Nevada formally transitioning new projects to the 3500 Series rack ecosystem while maintaining 3300 Series spare parts availability for installed base support.

3300 Series Full Catalog & Functionalities (SKU List)

Proximity Probes — Radial Vibration & Axial Position

• 330103-00-13-20-12-05: 5mm probe, 5m cable, standard radial/axial, -24VDC, 200mV/mil scale factor
• 330103-00-13-20-02-05: 5mm probe, 2m cable, short-reach radial vibration measurement
• 330103-00-13-20-05-05: 5mm probe, 5m cable, metric calibration, API 670 compliant
• 330103-00-13-20-09-05: 5mm probe, 9m cable, extended-reach radial vibration sensing
• 330104-00-13-20-12-05: 8mm probe tip, 5m cable, higher sensitivity radial vibration
• 330104-00-13-20-09-05: 8mm probe tip, 9m cable, large-shaft radial displacement
• 330105-02-12-05-02-00: 5mm probe, 2m armored cable, high-temperature process environment
• 330106-05-30-10-02-00: 5mm probe, 10m cable, differential expansion axial measurement
• 330180-91-00: 3300 XL 8mm proximity probe, extended linear range 0–4mm
• 330180-90-00: 3300 XL 5mm proximity probe, standard linear range, XL housing

Extension Cables

• 330130-045-00-00: 3300 Series extension cable, 4.5m, standard coaxial, BNC termination
• 330130-090-00-00: 3300 Series extension cable, 9m, standard coaxial, BNC termination
• 330130-045-02-00: 4.5m armored extension cable, high-vibration/abrasion environments

Proximitor Sensors (Signal Conditioners)

• 330180-51-00: 3300 XL Proximitor, 5mm probe compatible, -24VDC, 7.87V/mm output
• 330180-51-05: 3300 XL Proximitor, ATEX/IECEx certified, Zone 1 hazardous area
• 330100-90-00: Standard 3300 Proximitor, DIN rail mount, 5mm/8mm probe compatible
• 330100-90-05: Standard 3300 Proximitor, panel mount, intrinsically safe barrier compatible

Mounting Hardware & Accessories

• 21022-28-05-017-03: Dual axial probe housing assembly, bearing housing mount
• 330175-00-00: Probe mounting bracket, stainless steel, standard bearing cap

Quality Control for the 3300 Series Range

Each 3300 Series proximity probe assembly processed by DriveKNMS undergoes a structured verification protocol before dispatch:

• Coaxial impedance check: Extension cable and probe tip assembly verified at 50Ω ±5% using a calibrated TDR (Time Domain Reflectometer) to detect cable damage, connector oxidation, or impedance mismatch that would corrupt the Proximitor output signal.
• Static gap calibration: Probe tip positioned against a certified AISI 4140 steel target at 1.0mm, 1.27mm, and 2.0mm gaps. Output voltage verified against the 7.87 V/mm (200 mV/mil) scale factor ±1% tolerance.
• Dynamic frequency response: Probe assembly driven at 10 kHz oscillator frequency (standard 3300 Series carrier). Output linearity verified across the full 0–2.54mm measurement range.
• Proximitor supply current draw: Verified at -24 VDC nominal supply. Current draw outside the 12–18 mA specification range indicates internal oscillator fault.
• Connector and housing inspection: BNC connectors, probe tip threads (M10×1 standard), and cable jacket inspected for mechanical damage, corrosion, and seal integrity.
• Certification traceability: ATEX/IECEx-certified units verified against original certification documentation. Certification markings on housing inspected for legibility and completeness.