Bently Nevada 330878-91-00 3300 XL 11 mm Proximitor Sensor

The Bently Nevada 330878-91-00 is a critical component of the renowned 3300 XL 11 mm Proximitor Sensor System. Manufactured by Bently Nevada (now part of Baker Hughes), this Proximitor sensor is engineered to interface with 3300 XL 11 mm probes and extension cables to provide accurate, non-contact vibration and displacement measurements .

As part of the 3300 XL series, this sensor is designed for machinery protection and condition monitoring on critical rotating equipment, including steam turbines, compressors, and hydroelectric machinery .

Key Features and Benefits

Extended Linear Range: The 11 mm tip diameter provides a longer linear range than standard 8 mm systems. This makes the 330878-91-00 ideal for specific applications such as axial (thrust) position measurements, differential expansion monitoring, and rod position measurements on reciprocating compressors .

Improved RFI/EMI Immunity: The 3300 XL Proximitor features enhanced immunity to radio frequency and electromagnetic interference. This ensures signal integrity in electrically noisy environments and simplifies CE mark approvals without requiring special installation considerations .

Component Interchangeability: The system supports complete interchangeability of probes, extension cables, and the Proximitor sensor. Components do not require individual matching or bench calibration, significantly reducing maintenance and replacement downtime .

Robust Mechanical Design: Designed for harsh industrial environments, it utilizes SpringLoc terminal strips for fast and reliable field wiring. When paired with 3300 XL probes featuring ClickLoc connectors, the system ensures a secure connection that resists loosening from vibration .

Flexible Mounting: The Proximitor sensor features a thin-profile design that allows for versatile mounting options, including high-density DIN-rail installations or traditional panel mount configurations .

Technical Specifications (Typical for 3300 XL 11mm System)

System Output: 3.94 V/mm (100 mV/mil) 

Frequency Response: 0 to 8,000 Hz 

Linear Range: 4 mm (approx. 160 mils) 

Compatibility: Designed for use with 3300 XL 11 mm Probes and Extension Cables.

Common Applications

The Bently Nevada 330878-91-00 Proximitor is essential for protecting capital equipment by monitoring:

Radial vibration of fluid-film bearings .

Shaft axial (thrust) position.

Keyphasor* and speed measurements.

Differential expansion and case expansion in turbines .

For industries relying on API 670-compliant protection systems, the 3300 XL series remains the industry standard for reliability and precision .