Configured for radial and axial shaft displacement monitoring in Bently Nevada 3300 NSv series machinery protection systems, the Bently Nevada 330901-00-20-05-02-00 (330901 Proximity Probe) provides direct eddy-current proximity measurement for rotating machinery.

Suffix Breakdown & Model Matrix

Hardware Specifications

Eddy-Current Probe Scaling & Gap Voltage Characteristics

The 330901 NSv probe operates on the eddy-current principle, generating a high-frequency RF signal that induces eddy currents in the target conductive surface. The resulting impedance change is converted to a DC voltage proportional to the probe-to-target gap. Nominal scale factor is 200 mV/mil (7.87 V/mm) with a linear range extending to approximately 80 mils (2.03 mm) depending on target material and probe geometry. Gap voltage validation targets -10 VDC at the transducer output under standard calibration conditions. The probe exhibits stable performance across a wide temperature range with minimal thermal drift when properly installed. Cross-talk suppression is achieved through the coaxial ClickLoc connector design, which maintains signal integrity in electrically noisy environments typical of rotating machinery installations.

Ordering Info

• 1 x 330901-00-20-05-02-00 Proximity Probe (unarmored, 0.5 m cable, ClickLoc connector)

Field Installation Guidelines

• Verify probe tip is free of debris and damage before installation.
• Engage a minimum of 5 full threads of the 1/4-28 UNF fitting into the probe bracket or housing.
• Tighten to specified torque (refer to 3300 NSv system manual); do not overtighten.
• Ensure the probe tip does not contact the rotating shaft at any position throughout the full operating range.
• Route the coaxial cable away from high-voltage conductors and switching devices to minimize EMI.
• Terminate the cable shield at the signal conditioner end only (single-point ground) to prevent ground loops.
• Confirm the ClickLoc connector is fully seated and the locking mechanism is engaged.

Frequently Asked Questions

• Q: What is the nominal gap voltage target for this probe during calibration?

  A: The standard gap voltage target is -10 VDC at the transducer output when the probe is positioned at the mid-scale gap distance from the target surface.

• Q: Can this probe be used with 3300 XL series extension cables?

  A: No. The 330901 NSv probe uses a miniature coaxial ClickLoc connector and is designed specifically for the 3300 NSv system. It is not compatible with 3300 XL extension cables.

• Q: What is the linear measurement range of the 330901 probe?

  A: The linear range is approximately 80 mils (2.03 mm) total, with a scale factor of 200 mV/mil. The usable range may vary slightly based on target material properties.

• Q: Is the probe tip replaceable if damaged?

  A: No. The probe tip is integral to the sensor assembly. If the tip is damaged, the entire probe must be replaced.

• Q: What target materials are compatible with this eddy-current probe?

  A: The probe is calibrated for ferrous and non-ferrous conductive materials. Standard calibration targets are 4140 steel. Different materials will produce different scale factors.

• Q: Does the unarmored construction affect installation in harsh environments?

  A: The unarmored version is suitable for standard industrial environments. For areas with potential cable abrasion or chemical exposure, consider the armored variant of the NSv probe.

• Q: What is the function of the ClickLoc connector locking mechanism?

  A: The ClickLoc connector provides a secure, vibration-resistant connection that prevents accidental disengagement due to machinery vibration. Always verify the lock is fully engaged after connection.

• Q: Can this probe be hot-swapped while the system is operational?

  A: No. The probe and its signal conditioner should be installed and wired with the system de-energized. Verify gap voltage and signal integrity after installation before returning to service.