Description

The Bently Nevada 330850-50-00 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 330850-50-00 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 25.4 mm 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 “-50” and “-00” option codes define?

A: The option code -50 specifies a 5.0-meter total system length calibrated for standard panel mounting (incorporating integrated flat mounting holes instead of DIN-rail clips). The option code -00 designates the standard, non-hazardous commercial version, which lacks explosive-environment safety approvals (such as ATEX or IECEx).

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 “50” suffix provides integrated panel mount holes, you can screw the unit directly onto a flat surface or a metal sub-plate inside a field junction box. The isolated base design of the Proximitor housing ensures that the aluminum casing is isolated from the plate to prevent ground loop currents.
• 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.