Description

The Bently Nevada 330105-20-12-10-02-00 is a specialized 8 mm Reverse Mount proximity probe from the 3300 XL product family. Reverse mount probes are specifically engineered to be threaded into a machine housing, bearing block, or internal bracket from the inside out, or through the back of a specialized adapter sleeve. This configuration is ideal for applications where external access or radial space is severely restricted.

The 330105 series features English 3/8-24 UNF mounting threads. This specific configuration combines a 2.0-inch unthreaded portion with a 1.2-inch threaded case length (making a 3.2-inch overall body length) and features a standard 1.0-meter integral cable assembly.

Suffix Breakdown & Model Matrix

The alphanumeric suffix combination defines the specific mechanical, electrical, and regulatory configurations of this reverse mount hardware assembly:

• 330105: Base model for 3300 XL 8 mm Reverse Mount Proximity Probe with 3/8-24 UNF threads.
• 20: Unthreaded Length Option (20 = 2.0 inches).
• 12: Overall Case Length Option (12 = 1.2 inches).
• 10: Total Length Option (10 = 1.0 meter / 3.3 feet).
• 02: Connector and Cable-Type Option (02 = Miniature coaxial ClickLoc connector, standard coaxial cable).
• 00: Agency Approval Option (00 = Not required / no approvals).

Hardware Specifications

Eddy-Current Probe Scaling & Reverse Mounting Dynamics

During operation, high-frequency RF fields generated by the Proximitor loop penetrate the target surface. Because reverse mount probes are typically threaded into internal brackets or adapter sleeves inside the housing, meticulous care must be taken to ensure that surrounding sleeve surfaces do not cross into the probe tip’s wide RF path. To establish a stable operating baseline for rotor dynamics tracking, field engineers must validate that the gap voltage achieves a target value of -9 VDC to -10 VDC at the geometric center of the linear zone.

Frequently Asked Questions

Q: What extension cable configuration does this 1.0-meter probe require?

A: This 1.0-meter total length probe must be paired with a standard 3300 XL extension cable to complete the circuit back to the Proximitor sensor. For a standard 5.0-meter system loop, it requires a 4.0-meter extension cable; for a 9.0-meter system loop, it requires an 8.0-meter extension cable.

Q: Can this probe be swapped with a 330106 model?

A: Electrically they use the same 8 mm tip and 3300 XL electronics. However, mechanically they are completely incompatible because the 330105 utilizes an imperial 3/8-24 UNF reverse mount thread, while the 330106 series utilizes an M10x1 metric reverse mount thread.

Field Installation Guidelines

• Sleeve Clearance: Ensure the internal installation port or housing sleeve has a counterbore clearance diameter of at least 2 or more probe tip diameters (16 mm or 0.63 inches minimum) around the tip to prevent side-loading calibration anomalies.
• Torque Limits: When installing the 3/8-24 UNF reverse mount threaded case, do not exceed the maximum allowable tightening torque of 16.3 N·m (144 in·lb).
• Connector Integrity: Ensure the miniature coaxial ClickLoc connector faces remain completely free of moisture and process oil splash. Subsequently, twist the collar until a mechanical click occurs to confirm lock engagement.
• Shielding Protocols: Leave the coaxial cable shield floating at the probe end. Instead, execute terminal grounding solely at the instrument rack or the Proximitor isolation housing ground terminal block to eliminate ground loops.