Description

Configured for converting eddy-current gap variations into proportional analog DC voltages in Turbine Supervisory Instrumentation (TSI) systems, the Bently Nevada 330850-90-00 (330850 3300 XL 25 mm Proximitor Sensor) provides direct electrical execution.

Suffix Breakdown & Model Matrix

• 330850: Designates the base model for the 3300 XL 25 mm Proximitor Sensor.
• -90: Dictates a 9.0 meters (29.5 feet) total system length specifically configured for panel mounting.
• -00: Indicates standard commercial delivery without specialized hazardous area certifications.

Hardware Specifications

Eddy-Current Calibration and Gap Voltage Validation

The Bently Nevada 330850-90-00 actively scales high-frequency RF signals to match standard AISI 4140 steel targets. To perform proper gap validation, the technician first establishes a physical sensor-to-target distance that yields a midpoint nominal output. Specifically, this center range corresponds to a target voltage of approximately -6.5 VDC. Consequently, this calibration suppresses adjacent-channel cross-talk and preserves signal integrity during rapid rotor dynamic shifts.

Frequently Asked Questions

Q: Can the 330850-90-00 operate with a 5.0 meters probe and cable assembly?

A: No. The internal calibration of the 330850-90-00 expects a 9.0 meters total electrical length. Therefore, pairing this Proximitor with a 5.0 meters system mismatches impedance and invalidates the nominal 20 mV/mil scale factor.

Q: How does the isolated base of the panel mount housing prevent electrical noise?

A: The panel mount base provides complete galvanic isolation between the internal circuit and the mounting plate. As a result, this physical barrier blocks parasite ground loops from entering the signal path.

Field Installation Guidelines

• First, lock the probe-to-Proximitor connection with the integrated ClickLoc coaxial connector. Slide the connector sleeve into place to seal the RF junction. Furthermore, route all coaxial cables away from high-voltage AC lines to prevent electromagnetic interference.
• Next, mount the aluminum housing to a clean, flat sub-panel inside a weather-proof enclosure. Maintain at least 50.8 mm (2.0 inches) of clearance from adjacent high-frequency components to avoid parasitic coupling.
• Finally, verify the initial calibration. Connect a high-impedance digital multimeter to the OUT and COM terminals. Mechanically adjust the physical depth of the 25 mm proximity probe until the meter registers exactly -6.5 VDC.