The Bently Nevada 130938-01-10-01, also cataloged as the 130938 Vibration Probe, operates as a dedicated hardware component for noncontacting displacement and shaft vibration measurements within 3300 XL Proximity Transducer System platforms.

Bently Nevada 3300 XL Proximity Transducer System. Source: Instrumart

Part Number Configuration

The physical and electrical design of this 3300 XL vibration probe is defined by its specific option suffix codes:

• 130938: Base model identifier for the 3300 XL series proximity probe configuration (certified for Groups A, B, C, D hazardous areas).

• -01: Defines the specific body thread and unthreaded length physical parameters.

• -10: Specifies an integrated coaxial cable length of 1.0 m (39 in).

• -01: Features a standard miniature coaxial connector with integrated protector sleeve.

Hardware Specifications

Eddy-Current Probe Scaling and Rotor Dynamics Integration

The 130938-01-10-01 probe works on the physical principle of eddy-current probe scaling to measure micro-level changes in gap distance. When energized by the high-frequency RF signal from a 3300 XL Proximitor, the probe coil projects a localized magnetic field. As the rotating shaft shifts, it generates eddy currents on the target surface, causing impedance changes that the Proximitor decodes into an analog voltage output. This fast response makes the system suitable for analyzing high-speed rotor dynamics, including sub-synchronous vibration, shaft orbit patterns, and axial rotor position.

Achieving the rated linearity requires precise gap voltage validation during field installation. The technician must mechanically adjust the probe's thread position relative to the target until the quiescent output voltage measures -9.0 VDC (corresponding to a 1.27 mm mechanical gap). This step aligns the measurement at the center of the sensor's linear range, securing a stable 7.87 mV/micrometer scale factor and supporting cross-talk suppression between adjacent orthogonal probes.

Ordering Info

• 1 x Bently Nevada 130938-01-10-01 Vibration Probe

• 2 x Threaded mounting locknuts

• 1 x Connector protector sleeve

Field Installation Guidelines

• Verifying Probe Side ClearanceMaintain a physical radial clearance of at least 8.9 mm (0.35 in) between the probe tip and any surrounding machine casing to prevent electromagnetic field distortion.

• Grounding and Shielding RulesEnsure the coaxial shield is isolated from the machine housing and grounded only at the terminal block of the monitor rack. Slide the protective sleeve completely over the coaxial connection.

• Coaxial Cable Routing LimitsSecure the 1.0 m integrated lead along non-rotating surfaces using soft ties. Do not bend the coaxial cable tighter than a 25.4 mm (1.0 in) radius to avoid internal conductor deformation.

Frequently Asked Questions

• What target gap voltage is required for standard linear calibration?

  The probe position must be mechanically adjusted to register a target output of -9.0 VDC, centering it within the 2.0 mm linear operating range.

• Is this probe rated for installation in explosive atmospheres?

  Yes, the 130938 series holds hazardous area approvals for Class I, Division 1, Groups A, B, C, and D when installed with matching safety barriers.

• What is the standard target material assumed for the 7.87 mV/micrometer scaling?

  System calibration assumes a high-permeability AISI 4140 steel target. Other target alloys alter the scale factor and require recalibration.

• Can this 1.0 m probe be linked directly to a monitor without an extension cable?

  No, it must be matched with a 3300 XL extension cable to meet the total 5.0 or 9.0-meter system length required by the Proximitor.

• What occurs if the coaxial cable is bent below the minimum radius?

  Bending the cable below 25.4 mm deforms the internal dialectric layer, altering the system impedance and inducing signal noise.

• Does this model support hot-swapping while the protection rack is live?

  Yes, but disconnecting the coaxial plug breaks the current loop, causing the associated monitor channel to report a "Not OK" fault state.

• How does moisture or oil accumulation on the probe tip affect performance?

  Non-conductive oil on the tip does not alter the eddy-current field, but moisture containing metallic debris will cause signal offset.

• How is signal cross-talk suppressed in close multi-probe installations?

  Maintain a minimum spatial separation of 40 mm between adjacent 8 mm probe tips when mounted on the same mechanical plane.