Description

The Bently Nevada 330850-51-05 is a high-performance 3300 XL series proximity sensor engineered for a 25 mm transducer system. It is designed for applications that require an exceptionally wide linear measurement range, such as tracking differential expansion (DE) or axial thrust on large steam turbines, industrial compressors, and high-capacity fluid-film bearing machinery.

Operating on eddy-current principles, the sensor continuously converts high-frequency radio frequency (RF) gaps into a stable analog DC voltage proportional to the distance between the probe tip and the target material.

Hardware Specifications

Transducer Technology and Linear Range

The Bently Nevada 330850-51-05 relies on a robust internal oscillator/demodulator circuit that is highly resistant to radio frequency interference (RFI). By operating at a lower scale factor of 20 mV/mil (compared to the standard 200 mV/mil of 8 mm systems), this 25 mm Proximitor stretches the physical linear measurement envelope to a massive 12.7 mm (500 mils) range.

The system provides complete component interchangeability. You can pair this Proximitor with any compatible 3300 XL 25 mm probe and extension cable matching the calibrated 5.0-meter system configuration without performing any tedious manual bench calibration.

Frequently Asked Questions

Q: What specific hardware parameters do the “-51” and “-05” option codes define?

A: The option code -51 specifies a 5.0-meter total system length configured for high-density 35 mm DIN rail mounting. The option code -05 designates hazardous environment safety certifications, carrying global approvals such as ATEX, IECEx, and CSA for explosive and intrinsically safe areas.

Q: Can this 25 mm Proximitor drive long-distance field wiring runs?

A: Yes. Because the dynamic output impedance of the 330850 series is low (50 ohms), you can run standard three-conductor shielded triad cabling (16 to 24 AWG) up to 305 meters (1000 feet) from the sensor location to your 3500-series monitor rack.

Field Installation Guidelines

• Shielding and System Grounding: Connect the 25 mm probe or extension coaxial cable securely using the integrated, gold-plated ClickLoc connectors. Turn the connections finger-tight until you hear an audible click. Ensure that the coaxial cable outer shield is isolated from the local machine ground, maintaining a single-point instrument ground exclusively at the main monitoring panel.
• Mounting Setup: Since the “51” suffix indicates a DIN rail mount design, you can snap the unit directly onto a standard 35 mm DIN rail. The integrated mounting base provides built-in electrical isolation, preventing the aluminum housing from making contact with the rail and generating ground loops.
• Mechanical Calibration & Gap Setup: During field commissioning, mechanically gap the 25 mm probe relative to the target collar. Aim to set the static physical gap at the mid-point of the linear range. This correlates to an output voltage of roughly -6.5 VDC on your terminal block, leaving equal measurement headroom for both expansion and contraction.