Bently Nevada 330850-91-05 Proximitor Sensor

Bently Nevada 330850-91-05 Proximitor Sensor

The Bently Nevada 330850-91-05, also cataloged as the 3300 XL 25 mm Proximitor Sensor, serves as the primary 3300 XL Proximitor Sensor utilized to execute signal conditioning for large-scale displacement measurements across machinery protection platforms. The module accepts high-frequency inputs from a 25 mm eddy-current probe and provides a linear voltage output proportional to the physical gap distance for tracking differential expansion.

Hardware Specifications

Eddy-Current Probe Scaling & Rotor Dynamics

The 3300 XL 25 mm sensor utilizes specialized eddy-current probe scaling to handle an extended linear range of 12.7 mm, generating a nominal Average Scale Factor (ASF) of 0.787 V/mm. During field calibration, matching the sensor to a 9.0-meter system length requires rigid gap voltage validation (-10 VDC targets) across the mid-point of the physical span. This extended calibration envelope is necessary to accurately track long-stroke rotor dynamics and differential expansion on steam turbine casings, while internal shielding ensures cross-talk suppression between adjacent complementary sensors viewing the same measurement collar.

Frequently Asked Questions

Q: Can this sensor be paired with a standard 3300 XL 8 mm proximity probe?

A: No. The internal oscillator circuit and electrical scaling parameters of the 330850-91-05 are factory tuned specifically for the 3300 XL 25 mm probe. Pairing this device with an incorrect probe diameter will invalidate the scale factor and cause severe measurement tracking errors.

Q: What are the primary dual-transducer mounting options supported by this device's scale factor?

A: The sensor supports standard configurations including: dual transducers observing the same side of a collar for redundancy, complementary inputs on opposite sides of a collar to effectively double the measurable range, or ramp-tracking arrangements designed to compensate for cross-axis radial shaft movement.

Field Installation Guidelines

• DIN-Rail and Plate Isolation: Mount the Proximitor Sensor onto a standard 35 mm DIN rail or high-density bulkhead plate. Ensure the housing is electrically isolated from structural machine ground to prevent earth-loop noise injection into the signal path.
• Coaxial Terminal Torquing: Connect the 9.0-meter extension cable to the miniature coaxial interface. Ensure the coupling is secured finger-tight; do not utilize mechanical pliers which may crimp the internal dielectric layer.
• Field Potentiometer Field Limits: The zero and span curves are factory-calibrated. Field personnel must not alter the internal potentiometers unless performing a full bench re-verification with a calibrated micrometer kit and specific target metallurgy.