Configured for contactless displacement monitoring in 3500 Machinery Protection Systems, the Bently Nevada 330902-00-40-10-02-CN (330902 Proximity Probe) provides direct physical/electrical execution. This hardware converts the relative gap between the probe tip and a rotating metallic target into a proportional analog voltage signal. The system is engineered to provide high-resolution measurements of rotor position and vibration, particularly for small-diameter shafts where standard 8 mm probe footprints are constrained.

Suffix Breakdown & Model Matrix

• 330902: 3300 NSv Proximity Probe

• -00: Unthreaded Length option (0.0 inches of unthreaded probe sleeve)

• -40: Case Total Length option (4.0 inches total threaded case length)

• -10: Total Length option (1.0 meter system length)

• -02: Connector option (Miniature coaxial Click-Loc connector with fluid protection)

• -CN: Agency Approval option (China-specific compliance certification)

Hardware Specifications

Rotor Dynamics & Eddy-Current Precision

The 3300 NSv system relies on precise eddy-current probe scaling to ensure vibration data remains representative of machine health. During the setup phase, gap voltage validation is performed to achieve a -10 VDC target at the mid-point of the linear operating range. This ensures the signal swing is centered within the input range of the monitor module. Technicians must prioritize cross-talk suppression by maintaining adequate separation between probe tips, which prevents the excitation fields of adjacent sensors from distorting phase-angle and amplitude measurements.

Ordering Information

• One (1) 330902-00-40-10-02-CN Proximity Probe

• Two (2) 3/8-24 UNF-2A hex locknuts

• One (1) silicone connector protector sleeve

• Compliance and factory calibration documentation

Field Installation Guidelines

• Mounting Engagement: Ensure a minimum of five (5) full thread turns are engaged within the mounting bracket to secure the probe position under vibration.

• Gap Setting: Verify the static gap using a feeler gauge to ensure the probe tip does not contact the shaft during thermal expansion or mechanical deflection.

• Cable Management: Secure the coaxial lead to a static structural member at frequent intervals to minimize cable whip and prevent connector strain.

• Shield Grounding: Ground the coaxial shield at only one point—the monitor rack terminal—to prevent ground loops that introduce noise into the signal chain.

Delivery Information

• Delivery time: 2-7 days when payment finish.

• Dispatched via DHL/FEDEX/UPS.

• Anti-static industrial packaging used to ensure protection against impact and electrostatic discharge.

Frequently Asked Questions

• Can the 330902 probe be used with standard 3300 XL Proximitors?

  No. The NSv probe is designed specifically for the 3300 NSv Proximitor sensor due to different carrier frequencies and impedance characteristics.

• What is the consequence of exceeding the 1.5 mm linear range?

  Exceeding the range causes the signal to deviate from the linear slope, leading to distorted vibration waveforms and inaccurate amplitude measurement.

• Is this probe suitable for submerged oil service?

  Yes, provided the coaxial connector is protected by the silicone sleeve to prevent conductive fluids from bridging the connector pins and causing signal attenuation.

• Why does the probe output voltage increase with distance?

  The probe uses an inductive oscillator; as the target moves away, the loading on the coil decreases, shifting the output voltage closer to the supply voltage (-24 VDC).

• Can the probe cable be shortened in the field?

  No. Altering the cable length changes the impedance of the tuned circuit, which invalidates the factory calibration and significantly degrades measurement accuracy.

• How is probe health monitored in the 3500 system?

  The monitor constantly checks the gap voltage. Values outside the -1 VDC to -21 VDC range trigger a NOT OK status, indicating a fault or open circuit.

• Does the probe tip diameter affect the measurement?

  Yes. The 330902 tip is optimized for smaller targets than standard 8 mm probes, providing better resolution for small-diameter shaft applications.

• How can I verify the probe is functioning correctly?

  Measure the gap voltage at the Proximitor terminal. If the value is within the linear range and changes with shaft displacement, the probe circuit is healthy.