The Bently Nevada 330850-91-05, also cataloged as the 330850 Proximitor Sensor, operates as a dedicated hardware component for casing-to-shaft proximity signal conditioning within machine monitoring systems.

Ordering & Configuration Matrix

• 330850: 3300 XL 25 mm Proximitor Sensor
• 91: 9.0 meters (29.5 feet) system length
• 05: Multiple agency approval ratings

Hardware Specifications

TSI and Mechanical Dynamics

The 3300 XL series utilizes high-frequency eddy-current probe scaling to convert target proximity into a linear electrical output. System performance is contingent upon precise gap voltage validation, typically maintained at -10 VDC to ensure the probe operates within its linear measurement range. The sensor architecture includes active cross-talk suppression, permitting operation in multi-channel proximity arrays without mutual signal interference. Accurate rotor dynamics data acquisition relies on maintaining system integrity across the specified 9.0 m cable length.

Ordering Info

• 1 330850-91-05 Proximitor Sensor
• 1 Instruction and technical documentation packet

Field Installation Guidelines

• Mounting: Secure the sensor within an enclosure or on a DIN rail, ensuring the housing is protected from direct environmental exposure.
• Cabling: Use factory-terminated coaxial cables to ensure impedance matching; avoid sharp bends or mechanical stress on the ClickLoc connectors.
• Shielding: Terminate the cable shield at the designated ground reference to maintain RFI/EMI immunity in industrial environments.
• Verification: Confirm system calibration post-installation by checking the gap voltage at the sensor output terminals against expected mechanical clearance.

Frequently Asked Questions

• Is this sensor compatible with 8 mm probes?

  No. The 330850 Proximitor is specifically calibrated for 25 mm probes; electrical impedance mismatch will occur if connected to an 8 mm probe.

• What happens if the system cable length is modified in the field?

  System calibration is fixed to the 9.0 m length. Modifying cable length alters the circuit capacitance and inductance, leading to significant measurement errors.

• Can the Proximitor be hot-swapped?

  The unit does not support hot-swapping. Power must be disconnected from the loop to avoid electrical transients that may damage internal components.

• What is the impact of temperatures exceeding 100 deg C?

  Operating above the 100 deg C limit causes drift in the sensor scale factor and potential failure of internal electronic components.

• How does the Average Scale Factor (ASF) affect output?

  The 0.787 V/mm ASF is the constant ratio of output voltage change to input displacement; deviations indicate a fault in the probe or sensor loop.

• Does the "91" option include extension cables?

  The "91" code defines the total system length (9.0 m), which includes the probe, extension cable, and Proximitor sensor assembly.

• Are there specific grounding requirements for the sensor case?

  Yes. The sensor case must be connected to a clean instrument ground to maintain the signal-to-noise ratio required for precision vibration monitoring.

• What is the significance of the 20 mV/mil rating?

  This is the standard engineering unit sensitivity for the sensor, used by monitoring systems to interpret the raw voltage output as physical distance.