Bently Nevada 330880 Series Proximity Transducers

Technical Dossier

Product Details And Specifications

Bently Nevada 330880 Series Technical Notes

The Bently Nevada 330880 Series comprises a family of proximity transducers engineered for continuous, non-contact measurement of shaft vibration, position, and eccentricity in rotating machinery. These transducers are integral components of the 3300 XL monitoring system and have accumulated decades of installed base across the global heavy-process industries — including petrochemical refineries, nuclear power stations, offshore platforms, LNG terminals, and large-scale chemical plants. The 330880 series operates on the eddy-current principle, generating a radio-frequency field that responds to changes in the distance between the probe tip and a conductive target surface. Output is a DC voltage signal, typically –24 VDC at 200 mV/mil (7.87 V/mm) sensitivity, compatible with Bently Nevada 3300 XL proximitor/seismic monitors. The series is API 670 compliant, the governing standard for machinery protection systems in the petroleum, chemical, and gas industries, making it the default specification for turbomachinery OEM packages worldwide.

The Evolution of 330880 Architecture

The 330880 series is the direct successor to the earlier Bently Nevada 7200 and 3300 standard proximity probe families. The architectural transition from the 3300 standard to the 3300 XL platform — introduced in the mid-1990s — brought tighter manufacturing tolerances, extended temperature ratings, and improved EMI immunity. The 330880 designation specifically identifies the XL-generation probe body, which features a standardized 8 mm tip diameter and a threaded body for rigid installation in machinery housings. Cable lengths in the 330880 series are defined by the third and fourth numeric segments of the part number, allowing system integrators to specify exact extension cable lengths to match proximitor mounting distances without introducing signal attenuation. The series has entered a mature lifecycle phase: Bently Nevada (now a Baker Hughes company) continues to supply active variants, but a significant portion of the catalog — particularly non-standard cable lengths and early connector configurations — is classified as RFQ availability review or obsolete. Plants operating legacy turbomachinery with 3300 XL systems must source these components through specialist distributors to avoid forced system upgrades.

330880 Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified, commonly deployed models within the Bently Nevada 330880 proximity transducer series. Each entry reflects a distinct cable length, connector, or configuration variant:

330880-28-00-035-00-02: 8 mm probe, 5 m extension cable, standard connector, –24 VDC, 200 mV/mil output, API 670 compliant.
330880-28-00-035-00-00: 8 mm probe, 5 m extension cable, no connector (bare lead), standard XL proximitor interface.
330880-28-00-035-00-05: 8 mm probe, 5 m extension cable, armored cable variant for high-vibration environments.
330880-28-00-050-00-02: 8 mm probe, 7.62 m (25 ft) extension cable, standard connector, –24 VDC output.
330880-28-00-050-00-00: 8 mm probe, 7.62 m extension cable, bare lead termination.
330880-28-00-100-00-02: 8 mm probe, 15.24 m (50 ft) extension cable, standard connector, long-run installation.
330880-28-00-100-00-00: 8 mm probe, 15.24 m extension cable, bare lead, for remote proximitor mounting.
330880-28-00-200-00-02: 8 mm probe, 30.48 m (100 ft) extension cable, standard connector, extended-distance configuration.
330880-28-00-025-00-02: 8 mm probe, 3.81 m (12.5 ft) extension cable, standard connector, compact installation.
330880-28-00-025-00-00: 8 mm probe, 3.81 m extension cable, bare lead termination.
330880-28-05-035-00-02: 8 mm probe, 5 m extension cable, high-temperature probe body rated to 177°C (350°F).
330880-28-05-050-00-02: 8 mm probe, 7.62 m extension cable, high-temperature variant, standard connector.
330880-28-05-100-00-02: 8 mm probe, 15.24 m extension cable, high-temperature probe body, long-run.
330880-28-00-035-02-02: 8 mm probe, 5 m extension cable, reverse-mount configuration for axial position measurement.
330880-28-00-050-02-02: 8 mm probe, 7.62 m extension cable, reverse-mount, axial position variant.
330880-28-00-035-01-02: 8 mm probe, 5 m extension cable, differential expansion measurement configuration.
330880-28-00-100-02-02: 8 mm probe, 15.24 m extension cable, reverse-mount, long-run axial position.

Quality Control for the 330880 Range

Each 330880 proximity transducer processed by DriveKNMS undergoes a structured verification protocol designed around the specific electrical and mechanical characteristics of the eddy-current sensing system. Static sensitivity verification is performed using a calibrated gap-setting fixture, confirming the –200 mV/mil (–7.87 V/mm) output slope across the linear range (typically 0.25 mm to 2.25 mm gap). Proximitor compatibility is verified by pairing each probe with a 3300 XL proximitor module and confirming system scale factor within ±1% of the nominal value. Cable continuity and insulation resistance are tested at 500 VDC to detect any degradation in the coaxial extension cable. Connector integrity — including the standard Bently Nevada bayonet-style connector — is inspected for pin alignment, corrosion, and mechanical retention force. High-temperature variants (–05– designation) are additionally verified for probe body integrity and cable jacket condition. All test data is logged and retained for a minimum of five years.